JP5200790B2 - Developing device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device that develops a latent image using a developer, a process cartridge, and an image forming apparatus including these.

  Some image forming apparatuses such as copiers, facsimiles, printers, and multi-functional machines form monochrome images and color images. As a typical image forming method in an image forming apparatus for forming a color image, developer images having different colors are formed by a plurality of process cartridges, and these are sequentially transferred while being superimposed on an intermediate transfer member, and then transferred to a transfer sheet. There is a tandem method that transfers all of the images at once. This process cartridge is developed by supplying an image carrier on which an electrostatic latent image is formed, a charging member for charging the image carrier, and a developer as powder according to the electrostatic latent image pattern to the surface of the image carrier. In many cases, a developing device for forming the agent image and a cleaning device for cleaning the developer remaining on the photosensitive drum after the transfer are provided.

  The developing device includes a developer carrier that is disposed in contact with and opposite to the image carrier and supplies a one-component developer to the surface of the image carrier, and a developer supply member and a layer provided in contact with the developer carrier A regulating member and a developer storage chamber for storing the developer are provided. The intermediate transfer member is constituted by a belt, and the process cartridges of the respective colors are arranged side by side so as to face the intermediate transfer belt.

  In order to cope with the number of printed sheets of thousands in the developing device, it is generally necessary to fill the developer accommodating chamber with hundreds of tens of grams of developer. In the tandem color image forming apparatus, when the image carriers are arranged side by side in the horizontal direction, the image forming apparatus includes a developer carrier, a developer supply member, and a layer regulating member in order to design the image forming apparatus in a compact and compact manner. It is necessary to arrange a developer storage chamber above the developing head unit. However, when the developer storage chamber is provided above the developing head unit, all of the developer's own weight is applied to the developer carrier, the developer supply member, and the layer regulating member. As a result, the developer is compacted and aggregated around the developer carrying member and the developer supplying member, and there is a disadvantage that the developer circulation property and the developer supplying property to the developer carrying member are deteriorated.

  For this reason, there is also a developing device provided with a developer agitating member for agitating the developer in the vicinity of the developer carrying member and the developer supplying member to eliminate the circulation property and the compacted state. However, even if a developer stirring member is provided, it is not always a sufficient measure against the pressurization due to the developer's own weight from above, and depending on the powder characteristics of the developer to be used, consolidation and aggregation An image failure due to a circulation failure or a supply failure occurs due to the above.

  Therefore, in Patent Document 1, a developer storage chamber composed of an upper cover and a casing, a non-magnetic one-component developer, a developer supply member, an agitator in the developer storage chamber, a developer supply member, a layer regulating member, a development A developing device including an agent stirring member, a partition metal plate, and the like is described. In this developing device, the partition metal plate is formed to have a width that matches the width of the developer accommodating chamber, divides the developing device vertically, and has a plurality of supply ports. The developer in the upper developer accommodating chamber is partitioned. The developer is moved to an appropriate amount to the lower developer supply chamber divided by the metal plate, and the developer in the lower developer supply chamber is always set to have a capacity of about 30 to 80 g.

JP 2001-194 483 A

  However, as in Patent Document 1, a wall is provided with a partition metal plate at the boundary between the developer carrier, the developer supply member, the layer regulating member, and the developer agitating member, and the developer storage chamber. When the wall is provided with a supply port for supplying the developer from the developer storage chamber to the developer supply chamber, and when a stirring member is provided above the supply port, the developer supply chamber and the developer storage are provided. Since only one wall with a supply port is inserted between the chamber and the chamber, the developer is supplied when the bulk density of the developer in the developer supply chamber decreases. If the developer is excessively supplied to the chamber, the density of the developer around the developer carrier and the developer supply member increases, and problems such as a decrease in developer circulation and supply performance may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device and a process cartridge that can improve the circulation and supply of the developer by supplying an appropriate amount of developer from the developer storage chamber to the developer supply chamber. .
It is an object of the present invention to provide an image forming apparatus that includes the developing device and the process cartridge described above, thereby preventing image defects due to poor supply of the developer and obtaining a good image. To do.

  In order to achieve the above object, in the present invention, a developer conveyance auxiliary chamber having two or more walls is provided between the developer supply chamber and the developer storage chamber, and the developer supply chamber and the developer conveyance auxiliary chamber are further provided. Further, by defining the opening position of the developer supply port provided on the wall between the developer conveyance auxiliary chamber and the developer storage chamber, the developer is excessively supplied from the developer storage chamber to the developer supply chamber. I try to prevent it.

  In other words, the invention according to claim 1 can be rotated to supply a developer carrier that is rotatably provided in proximity to or in contact with the image carrier, and to supply the developer as powder on the developer carrier. A developer supply member, a developer supply chamber having a developer agitating member provided in a non-contact and rotatable manner with the developer carrier and the developer supply member above the developer supply member, and a developer supply; A developer storage chamber disposed above the chamber for storing the developer and having a rotatable agitator for stirring the developer; and a developer on the developer support in contact with the developer support And a developer regulating chamber for developing the electrostatic latent image formed on the image carrier by applying a predetermined voltage to the developer carrier. Developer transport that adjusts the transport amount of developer between the developer supply chamber One or more auxiliary chambers are provided, and each boundary wall between the developer storage chamber, the developer conveyance auxiliary chamber, the developer conveyance auxiliary chamber, and the developer supply chamber has a supply port capable of conveying the developer. It is a feature.

According to the first aspect of the present invention, the developer agitation wherein the boundary wall separating the developer transport auxiliary chamber and the developer supply chamber is formed of a flexible sheet-like member and is disposed in the developer supply chamber. It arrange | positions so that it may contact a member regularly, It is characterized by the above-mentioned.

The invention according to claim 2 is characterized in that a supply port of a boundary wall separating the developer conveyance auxiliary chamber and the developer supply chamber is provided in a vertical direction at a lower portion of the developer conveyance auxiliary chamber.

According to a third aspect of the present invention, the supply port of the boundary wall separating the developer conveyance auxiliary chamber and the developer supply chamber is a side surface of the developer conveyance auxiliary chamber in which the direction of the force applied by the rotation of the developer agitating member is set. It is provided on the side.

According to a fourth aspect of the present invention, the developer repose angle measured by a measuring instrument is θ, the maximum width of the cross section perpendicular to the longitudinal direction of the developer transport auxiliary chamber is w, and the developer transport from the position that forms the maximum width w. When the height to the bottom of the auxiliary chamber is h, w × tan θ = 4h is satisfied.

The invention according to claim 5, the supply port of the boundary wall that separates the developer conveying auxiliary chamber and the developing agent storage chamber, characterized in that is not provided at the top of the developer transport auxiliary chamber, according to claim 6 invention, the supply port of the boundary wall that separates the developer conveying auxiliary chamber and the developing agent storage chamber, characterized in that provided below the rotation center of the agitator, the invention according to claim 7, developing The supply port of the boundary wall that separates the agent storage chamber and the developer conveyance auxiliary chamber is provided above the lowest position of the agitator.

The invention according to claim 8, characterized in that arranged rotatably auxiliary chamber developer stirring member for stirring the developer inside said developer transport auxiliary chamber, the invention of claim 9, wherein the auxiliary chamber The developer agitating member is arranged in the developer conveyance auxiliary chamber so as to periodically contact and press a boundary wall separating the developer conveyance auxiliary chamber and the developer supply chamber.

The invention according to claim 1 0 comprising at least an image bearing member and the developing device, a process cartridge is detachably attached to the image forming apparatus main body, according to any one of claims 1 as a developing device 9 It has a developing device.

According to claim 1 1 invention is characterized by comprising a process cartridge according to claim 1 0, wherein.

  According to the present invention, the developer transport auxiliary chamber is provided in the path for supplying the developer from the developer storage chamber to the developer supply chamber, thereby preventing the developer from being supplied to the developer supply chamber at a time. An effect is obtained. In addition, by preventing the developer from being supplied to the developer supply chamber at once, the load on the developer applied to the developer carrier, the developer supply member, and the layer regulating member is reduced, and the developer supply is poor. It is possible to obtain a good image by preventing the occurrence of image defects due to the above.

  According to the present invention, the boundary wall that separates the developer conveyance auxiliary chamber and the developer supply chamber, which is the lower side of the developer conveyance auxiliary chamber, is formed of a flexible sheet-like member, and the sheet-like member is stirred by the developer. Due to the contact with the member, the flexible sheet-like member is vibrated or deformed when periodically contacting the developer stirring member, and the effect of preventing the developer from aggregating in the lower part of the developer conveyance auxiliary chamber is effective. is there. In this case, the supply of the developer from the developer storage chamber to the developer supply chamber is performed without stagnation, and a good image free from image defects can be obtained.

  According to the present invention, the supply port of the boundary wall separating the developer conveyance auxiliary chamber and the developer supply chamber is provided in the vertical direction at the lower portion of the developer conveyance auxiliary chamber, so that the vibration caused by the developer agitating member can be provided. Thus, an effect of efficiently supplying the developer to the developer supply chamber can be expected.

  According to the present invention, the developer agitating chamber is provided with a supply port provided in a boundary wall separating the developer supply auxiliary chamber and the developer supply chamber in the direction of the force applied by the rotation of the developer agitating member. The force that deforms the member is used to supply the developer to the developer supply chamber, and the developer is prevented from being excessively supplied to the developer supply chamber when the developing device stops. The effect can be expected.

  According to the present invention, the developer supply port provided in the lower portion of the developer conveyance auxiliary chamber has the repose angle θ of the developer, the maximum width w of the cross section perpendicular to the longitudinal direction of the developer conveyance auxiliary chamber, and the maximum width w. By setting the height h from the formed position to the bottom of the developer conveyance auxiliary chamber to satisfy the condition of w × tan θ = 4h, the developer remains in a piled state on the boundary wall surface in the developer conveyance auxiliary chamber. Even in this case, it becomes possible to break up the piled developer by receiving the force when the boundary wall between the developer conveyance auxiliary chamber and the developer supply chamber vibrates and deforms, and the developer conveyance auxiliary chamber The effect of reducing the amount of remaining developer can be expected.

  According to the present invention, by providing a space between the uppermost part of the developer conveyance auxiliary chamber and the supply port of the developer storage chamber, it becomes possible to reduce the developer filling rate of the developer conveyance auxiliary chamber, The effect of preventing the developer from becoming consolidated in the developer replenishment auxiliary chamber can be expected, and the supply of the developer from the developer storage chamber to the developer supply chamber is performed without delay, and there is no image loss An image can be obtained.

  According to the present invention, by providing the developer supply chamber and the developer supply port provided in the developer conveyance auxiliary chamber below the rotation center of the agitator, the developer conveyance chamber can be used by utilizing the conveyance force of the agitator. The developer can be efficiently supplied to the developer conveyance auxiliary chamber, and the effect of reducing the amount of developer remaining in the developer accommodating chamber can be expected.

  According to the present invention, the supply port for replenishing the developer provided in the second developer replenishment control member is located above the lowest position of the agitator (above the position where the wings of the agitator are lowest). By providing, it is possible to prevent the developer from flowing into the developer replenishment auxiliary chamber at the same time and to prevent the developer from remaining in the developer storage chamber due to the rotation of the agitator.

  According to the present invention, the auxiliary chamber developer stirring member is rotatably provided in the developer conveyance auxiliary chamber, thereby reducing the bulk density of the developer in the developer conveyance auxiliary chamber and improving the flowability of the developer. It can be expected that the developer is consolidated and aggregated in the developer conveyance auxiliary chamber, thereby reducing the supply failure to the developer supply chamber.

  According to the present invention, the auxiliary chamber developer agitating member is disposed in the developer conveyance auxiliary chamber so as to periodically contact and press the boundary wall separating the developer conveyance auxiliary chamber and the developer supply chamber. By rotating the developer stirring member, the boundary wall surface is deformed and vibrated, and the effect of efficiently supplying the developer in the developer conveyance auxiliary chamber to the developer supply chamber can be expected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an image forming apparatus 100 including a plurality of process cartridges 1 including a developing device 4 according to the present invention. In this embodiment, in order to form toner images of yellow, magenta, cyan, and black, four process cartridges 1 are arranged in a horizontal row, and the image forming unit is configured. The components related to yellow, magenta, cyan, and black are identified by being assigned Y, M, C, and K, respectively. For example, yellow, magenta, cyan, and black process cartridges are indicated as process cartridges 1Y, 1M, 1C, and 1K, respectively, and yellow, magenta, cyan, and black developing devices are indicated as developing devices 4Y, 4M, 4C, and 4K, respectively. . The configuration of each process cartridge and the developing device is basically the same except that the color of the toner to be used is different. For this reason, the description of Y, M, C, and K is omitted except for cases relating to color image formation.

  Each process cartridge 1 has a structure in which a photosensitive drum 2 as an image carrier, a charging roller 3 as a charging member, a developing device 4 and a cleaning unit 5 are integrally coupled. Each process cartridge 1 is detachable from the image forming apparatus main body 100a, and can be detached from the image forming apparatus main body 100a and replaced by releasing each stopper (not shown).

  Each photosensitive drum 2 is rotated counterclockwise by a driving unit (not shown). Each charging roller 3 is in pressure contact with the surface of each photosensitive drum 2, and is driven to rotate by the rotation of the photosensitive drum 2.

  A predetermined bias is applied to each charging roller 3 by a high voltage power source (not shown) to charge the surface of the photosensitive drum 2. In this embodiment, a contact charging method in which the charging roller 3 is brought into contact with the charging roller as a charging member is used. However, a non-contact charging method in which each charging member and each photosensitive drum are charged in a non-contact state may be used. .

  An exposure unit 6 disposed above each process cartridge 1 exposes each photosensitive drum 2 based on image information, and forms an electrostatic latent image on the surface of each photosensitive drum 2. In this embodiment, a laser beam scanner system using a laser diode is used for the exposure means 6, but a configuration using an LED array or the like may be used.

  The developing device 4 uses a one-component contact developing method, and visualizes the electrostatic latent image on the photosensitive drum 2 as a toner image of each color. The developing device 4 is configured to be supplied with a predetermined developing bias from a high voltage power source (not shown). Each cleaning means 5 is a well-known one for cleaning the transfer residual toner on the surface of the photosensitive drum 2.

  The process cartridges 1Y, 1C, 1M, and 1K for each color of yellow, cyan, magenta, and black are arranged in parallel in the moving direction of the intermediate transfer belt 7 above the intermediate transfer belt 7 that serves as an intermediate transfer member, and sequentially in the middle. A visible image is formed on the transfer belt 7. Inside the intermediate transfer belt 7, primary transfer rollers 8 are disposed so as to correspond to the respective photosensitive drums 2. A primary transfer bias is applied from the primary transfer roller 8 between the intermediate transfer belt 7 and each photosensitive drum 2 by a high voltage power source (not shown), and a developer image on the surface of each photosensitive drum 2 is applied to the surface of the intermediate transfer belt 7. Transcript. The intermediate transfer belt 7 is configured to be rotated in the clockwise direction in the drawing by a drive motor (not shown), and forms a full-color image by sequentially transferring the visible images of the respective colors on the belt surface. To do.

  A secondary transfer portion is formed between the secondary transfer roller 9 and the intermediate transfer belt 7 arranged on the downstream side in the moving direction of the intermediate transfer belt 7. Here, a full color image formed on the intermediate transfer belt 7 is transferred onto a sheet 10 as a transfer material by applying a predetermined voltage via a secondary transfer roller 9 by a secondary transfer bias applying means (not shown). The The sheet 10 on which the full-color image has been transferred is fixed with the image of the developer transferred onto the sheet 10 by heat and pressure by the fixing device 12 and is discharged to the paper discharge unit 12 on the upper part of the image forming apparatus main body 100a. The developer remaining on the intermediate transfer belt 7 without being transferred onto the paper 10 by the secondary transfer roller 9 is collected by the transfer belt cleaning means 11.

Next, the structure of the process cartridge 1 provided with the developing device 4 which is a main part of the present invention will be described. Since the configuration of each process cartridge 1 is the same except that the color of the toner that is a developer included in the developing device is different, FIG. 2 will be described using one developing device.
(First embodiment)
The developing device 4 includes a developer storage chamber 101 that stores toner T serving as a developer, a developer supply chamber 102 provided below the developer storage chamber 101, a developer storage chamber 101, and a developer supply chamber 102. Is provided with a developer conveyance auxiliary chamber 100 formed therebetween. Below the developer supply chamber 102, a rotatable developing roller 103 serving as a developer carrying member, a layer regulating member 104 provided in contact with the developing roller 103, and a rotatable supply roller serving as a developer supplying member 105 is provided. The developing roller 103 is disposed in contact with the surface of the photosensitive drum 2, and a predetermined developing bias is applied from a high voltage power source (not shown).

  A developer stirring member 106 is provided in the developer storage chamber 101. A boundary wall 111 is provided between the developer storage chamber 101 and the developer conveyance auxiliary chamber 110 so as to separate them, and the boundary wall 111 can transport the toner T, that is, the first wall that can pass therethrough. A supply port 113 is provided. For this reason, the toner T stored in the developer storage chamber 101 is supplied from the first supply port 113 to the developer transport auxiliary chamber 110 and excessively supplied to the developer transport auxiliary chamber 110. Is prevented.

  A boundary wall 112 is provided between the developer conveyance auxiliary chamber 110 and the developer supply chamber 102, and the second wall capable of conveying, that is, passing through the toner T, is provided on the boundary wall 112. A supply port 114 is provided. For this reason, the toner T supplied to the developer conveyance auxiliary chamber 110 is supplied from the second supply port 114 to the developer supply chamber 102 and is prevented from being excessively supplied to the developer supply chamber 102. Has been.

  An agitator 115 for preventing the toner T from aggregating is rotatably disposed in the center of the developer storage chamber 101. The agitator 115 is configured to rotate counterclockwise in FIG. 2 by driving means (not shown).

  The surface of the supply roller 105 is covered with a foam material having a structure having a plurality of holes (cells), and the toner T conveyed into the developer supply chamber 102 is efficiently attached and taken in, The developer is prevented from being deteriorated due to pressure concentration at the contact portion with the developing roller 103. The foamed material is set to have an electric resistance value of 3 to 14 Ω. An offset voltage is applied to the supply roller 105 as a supply bias with the same polarity as the charging polarity of the toner T with respect to the potential of the developing roller 103. This supply bias acts in a direction in which the toner T preliminarily charged at the contact portion with the developing roller 103 is pressed against the developing roller 103. However, the polarity of the voltage applied to the supply roller 105 is not limited to this, and the same potential or polarity as that of the developing roller 103 may be reversed depending on the type of toner T.

  The supply roller 105 is rotated counterclockwise in FIG. 2 by a driving means (not shown), and has a function of applying and supplying the toner adhered to the surface thereof to the surface of the developing roller 103.

  As the developing roller 103, a roller coated with an elastic rubber layer is used, and a surface coat layer made of a material that is easily charged to a polarity opposite to that of the toner T is provided on the surface thereof. The elastic rubber layer is set to a hardness of 50 degrees or less according to JIS-A in order to keep the contact state with the photosensitive drum 2 uniform, and further, an electric resistance of 3 to 10 Ω in order to act a developing bias. Is set to a value. The surface roughness of the developing roller 103 is set to 0.2 to 2.0 μm in Ra, and a necessary amount of toner T is held on the surface. The developing roller 103 is rotated counterclockwise by a driving unit (not shown), and conveys the toner T held on the surface thereof to a position facing the layer regulating member 104 and the photosensitive drum 2.

  The layer regulating member 104 is made of a metal leaf spring material such as SUS304CSP, SUS301CSP, or phosphor bronze, and its free end is brought into contact with the surface of the developing roller 103 with a pressing force of 10 to 100 N / m. The developer that has passed under pressure is thinned and charged by triboelectric charging. Further, a voltage that is offset to the same polarity as the charging polarity of the toner T with respect to the potential applied to the developing roller 103 is applied to the layer regulating member 104 as a regulating bias in order to assist frictional charging.

  The photosensitive drum 2 is driven to rotate clockwise from FIG. 2 by a driving unit (not shown). Accordingly, the surface of the developing roller 103 moves in the same direction as the traveling direction of the photosensitive drum 2 at a position facing the photosensitive drum 2.

  The thinned toner T on the developing roller 103 is conveyed to a position facing the photosensitive drum 2 by the rotation of the developing roller 103, and the developing bias applied to the developing roller 103 and the electrostatic on the photosensitive drum 2. In accordance with the latent image electric field formed by the latent image, it moves to the surface of the photosensitive drum 2 and is developed. A sealing seal 109 is provided in contact with the surface of the developing roller 103 at a portion where the toner T not developed on the photosensitive drum 2 and remaining on the developing roller 103 returns to the developer supply chamber 102 again. The toner T is sealed so as not to leak out of the developing device 4.

  As shown in FIG. 3, the first supply port 113 formed in the boundary wall 111 (first wall surface) provided between the developer storage chamber 101 and the developer conveyance auxiliary chamber 110 is a developing device. 1 and at least one of them in the longitudinal direction (width direction) W. The toner T is supplied from the developer storage chamber 101 to the developer transport auxiliary chamber 110, and the toner T remains in the developer storage chamber 101. The toner T is prevented from being excessively supplied to the developer conveyance auxiliary chamber 110. The toner supply amount from the developer storage chamber 101 to the developer conveyance auxiliary chamber 110 can be adjusted by the number and size of the first supply ports 113.

  A second supply port 114 formed in a boundary wall 112 (second wall surface) provided between the developer conveyance auxiliary chamber 110 and the developer supply chamber 102 located below the developer conveyance auxiliary chamber 110 is provided in the developing device 4. One or more are provided in the longitudinal direction (width direction) W to supply the toner T from the developer conveyance auxiliary chamber 110 to the developer supply chamber 102, and without the toner T remaining in the developer conveyance auxiliary chamber 110. In addition, the toner T is prevented from being excessively supplied to the developer supply chamber 102. The toner supply amount from the developer conveyance auxiliary chamber 110 to the developer supply chamber 102 can be adjusted by the number and size of the second supply ports 114.

  Although not shown, the third wall surface is divided into one or more developing devices (longitudinal direction (width direction) W of 4) in the developer conveyance auxiliary chamber 110 or perpendicular to the longitudinal direction of the developing device 4. The developer conveyance auxiliary chamber 110 may be divided into two or more chambers so as to be divided into one or more in the direction.

As described above, by providing the developer transport auxiliary chamber 110 in the path for supplying the toner T from the developer storage chamber 101 to the developer supply chamber 102, the toner T is supplied to the developer supply chamber 102 at a time. Can be prevented. Further, by preventing the toner T from being supplied to the developer supply chamber 102 at a time, the load of the toner T applied to the developing roller 103, the supply roller 105, and the layer regulating member 104 is reduced. A good image can be obtained by preventing the occurrence of image defects.
(Second Embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. 4A shows a state in which the developer agitating member 106 and the boundary wall 112 are not in contact with each other, and FIG. 4B shows a state in which the developer agitating member 106 is in rotation and in contact with the boundary wall 112. Each is shown.

  In this embodiment, the boundary wall 112 is formed of a flexible sheet-like member, and is in a state in which the developer agitating member 106 disposed in the developer supply chamber 102 is in regular contact with a part of the boundary wall 112, The boundary wall 112 is arranged or configured so that the shape of the boundary wall 112 is deformed or vibrated by the rotational movement of the developer stirring member 106.

  With such a configuration, the boundary wall 112 is deformed or vibrated, whereby the toner T in the developer conveyance auxiliary chamber 110 is supplied to the developer supply chamber 102 and the toner T is contained in the developer conveyance auxiliary chamber 110. It is possible to prevent the inner lower portion 110a from being agglomerated or adhering to the wall surface of the boundary wall 112 and remaining. Further, since the supply of the toner T from the developer storage chamber 101 to the developer supply chamber 102 is performed without stagnation, a good image without image defects can be obtained.

  In this embodiment, the second supply port 114 is opened in the direction of gravity (vertical direction) at the position of the lowermost portion 112a of the boundary wall 112 as shown in FIGS. 4 (a) and 4 (b). Is formed. Therefore, the toner T having increased fluidity due to the deformation or vibration of the boundary wall 112 is easily supplied efficiently to the developer supply chamber 102 by the gravitational action.

In this embodiment, the developer stirring member 106 has a flat paddle shape, but may be a screw shape or a combination of a screw shape and a flat plate shape.
(Third embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. FIG. 5A shows a state where the developer agitating member 106 and the boundary wall 112 are not in contact with each other, and FIG. 5B shows a state where the developer agitating member 106 is rotating and in contact with the boundary wall 112. Each is shown.

In this embodiment, the second supply port 114 is provided in the boundary wall 112 by opening the side surface 110 b of the developer conveyance auxiliary chamber 110. The opening direction of the second supply port 114 is directed to the direction in which the boundary wall 112 is deformed by the force when the developer stirring member 106 rotates, and the boundary wall 112 is moved by the rotational movement of the developer stirring member 106. The toner T in the developer conveyance auxiliary chamber 110 is supplied to the developer supply chamber 102 by the deformation movement. Therefore, it is possible to prevent the toner from being excessively supplied to the developer supply chamber 102 when the developing device 4 is stopped.
(Fourth embodiment)
As shown in FIG. 6A, the repose angle of the toner T, which is the developer according to this embodiment, was measured by a measuring device (not shown). The measuring device is a powder tester made by Hosokawa Micron. The angle of repose θ is defined by the substrate horizontal surface 117a and the wall surface 116a of the toner T crest 116 in the cross section of the toner T crest 116 formed when the toner T is dropped onto the horizontal substrate 117 by this powder tester. It is a horn.

In the developing device 4 according to the present embodiment, when the toner T having the characteristic of the repose angle θ is used, a width W that maximizes a cross section perpendicular to the longitudinal direction (width direction) of the developer conveyance auxiliary chamber 110, The height h from the position where the developer conveyance auxiliary chamber 110 forms the maximum width W to the bottom 110a satisfies the following conditional expression “w × tan θ = 4h”. By satisfying such a condition, when the boundary wall 112 is deformed or vibrated and the fluidity of the toner T is increased, the toner T does not remain in the developer conveyance auxiliary chamber 110 and the developer supply chamber 102 can be supplied. That is, even when the toner T remains in a piled state in the lower portion 110a in the developer conveyance auxiliary chamber 110, the boundary wall 112 between the developer conveyance auxiliary chamber 110 and the developer supply chamber 102 vibrates and deforms. The toner T in a piled state can be broken by receiving the force at the time, and the amount of the toner T remaining in the developer conveyance auxiliary chamber 110 can be reduced.
(Fifth embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. In this embodiment, the arrangement location of the first supply port 113 is defined. That is, the first supply port 113 is provided at a position lowered by the height Ha from the uppermost portion 110c of the developer conveyance auxiliary chamber 110, and satisfies the condition of Ha> 0. That is, when the toner T is supplied to the developer conveyance auxiliary chamber 110, a space corresponding to the height Ha is always provided in the developer conveyance auxiliary chamber 110. For this reason, the toner T is not completely filled in the developer conveyance auxiliary chamber 110.

By not providing the first supply port 113 in the uppermost part 110c of the developer conveyance auxiliary chamber 110 in this way, the bulk density of the toner T in the developer conveyance auxiliary chamber 110 is reduced when the developing device 4 is stopped. Even when the toner T is excessively supplied from the developer storage chamber 101 to the developer conveyance auxiliary chamber 110 while the toner T is stopped, a space in which the toner T moves when the developing device 4 operates again can be maintained. Therefore, the compaction and aggregation of the toner T can be suppressed, the supply of the toner T from the developer storage chamber 101 to the developer supply chamber 102 can be performed without stagnation, and a good image free from image defects can be obtained. can do.
(Sixth embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. In this embodiment, the first supply port 113 is provided at a position lowered by a height Hb from the rotation center P of the rotatable agitator 115 provided in the developer containing chamber 101, and Hb ≧ 0. Meet the conditions. That is, by providing the first supply port 113 below the rotational center of the agitator 115, the toner T in the developer storage chamber 101 is pushed out in the rotational direction of the agitator 115 by the rotational motion of the agitator 115, and the force The toner T can be sent out to the developer conveyance auxiliary chamber 110. That is, the toner T can be efficiently supplied from the developer storage chamber 101 to the developer transport auxiliary chamber 110 using the transport force of the agitator 115 and the amount of developer remaining in the developer storage chamber 101 can be reduced. it can.
(Seventh embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. In the present embodiment, the first supply port 113 is provided at a position raised by a height Hc from the lowest part when the blades of the rotatable agitator 115 provided inside the developer storage chamber 101 rotate. And the condition of Hc ≧ 0 is satisfied. That is, if the lowermost portion of the tip 115a when the agitator 115 rotates is, for example, the bottom 101a of the developer storage chamber 101, the first supply port 113 is provided above the bottom 101a, whereby the agitator 115 is rotated. The toner T in the developer storage chamber 101 can be transported by movement, and the toner T can be supplied to the developer transport auxiliary chamber 110 from the first supply port 113. Therefore, it is possible to prevent the toner T from flowing into the developer replenishment auxiliary chamber 110 at a time and to prevent the toner T from remaining in the developer storage chamber 101 due to the rotation of the agitator 115.
(Eighth embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. In this embodiment, an auxiliary chamber developer stirring member 118 having a flat plate shape, a screw shape, a rod shape, or a composite shape thereof is rotatably provided inside the developer conveyance auxiliary chamber 110. The auxiliary chamber developer stirring member 118 is configured to be rotated by a driving means (not shown). Therefore, when the auxiliary chamber developer agitating member 118 rotates, the toner T in the developer conveyance auxiliary chamber 110 is agitated, the bulk density of the toner T is lowered, and the fluidity is improved. When the fluidity of the toner T is improved in this way, the toner T hardly remains in the developer conveyance auxiliary chamber 110 and can be supplied to the developer supply chamber 102. For this reason, the toner T is consolidated and aggregated in the developer conveyance auxiliary chamber 110, and supply failure to the developer supply chamber 102 can be reduced.
(Ninth embodiment)
The configuration of the process cartridge 1 and the developing device 4 according to this embodiment will be described with reference to FIG. 11A shows a state in which the auxiliary chamber developer stirring member 118 and the boundary wall 112 are not in contact with each other, and FIG. 11B shows a state in which the auxiliary chamber developer stirring member 118 rotates and contacts the boundary wall 112. Each state is shown.

  In this embodiment, the auxiliary chamber developer stirring member 118 is disposed near the boundary wall 112 in the developer conveyance auxiliary chamber 110 so as to periodically come into contact with the boundary wall 112. As described above, when the auxiliary chamber developer agitating member 118 is disposed near the boundary wall 112 in the developer conveyance auxiliary chamber 110, when the auxiliary chamber developer agitating member 118 rotates, the auxiliary chamber developer agitating member 118 periodically contacts the boundary wall 112 and is flexible. The boundary wall 112 formed of a flexible sheet material can be deformed, and the toner T inside the developer conveyance auxiliary chamber 110 can be efficiently supplied to the developer supply chamber 102 while stirring.

1 is a schematic configuration diagram illustrating an example configuration of an image forming apparatus in which a process cartridge including a developing device according to the present invention is detachable. FIG. 2 is an enlarged view showing a configuration of a developing device and a process cartridge according to the first embodiment of the present invention. FIG. 2 is an enlarged perspective view showing a partial configuration of a developing device and a process cartridge according to the first embodiment. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 2nd Embodiment of this invention, (a) The state which a developer stirring member and a boundary wall do not contact is shown, (b) is a developer stirring member Shows a state of rotating and contacting the boundary wall. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 3rd Embodiment of this invention, (a) A developer stirring member and a boundary wall show a non-contact state, (b) is a developer stirring member Shows a state of rotating and contacting the boundary wall. (A) is an enlarged view for explaining the angle of repose of the developer, and (b) is an enlarged view showing configurations of a developing device and a process cartridge according to the fourth embodiment of the present invention. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 5th Embodiment of this invention. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 6th Embodiment of this invention. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 7th Embodiment of this invention. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 8th Embodiment of this invention. It is an enlarged view which shows the structure of the developing device and process cartridge which concern on the 9th Embodiment of this invention, (a) Auxiliary chamber developer stirring member and a boundary wall show a non-contact state, (b) is an auxiliary chamber The state which the developer stirring member is rotating and contacting the boundary wall is shown.

Explanation of symbols

1 (Y, M, C, K) Process cartridge 2 (Y, M, C, K) Image carrier 4 (Y, M, C, K) Developing device 100 Image forming device 100a Image forming device main body 101 Developer storage Chamber 102 developer supply chamber 103 developer carrier 104 layer regulating member 105 developer supply member 106 developer agitating member 115 agitator 110 developer conveyance auxiliary chamber 110a bottom of developer conveyance auxiliary chamber 110b side surface of developer conveyance auxiliary chamber 110c Uppermost part 111, 112 of boundary wall 113, 114 Supply port 118 Auxiliary chamber developer stirring member h Height P Rotation center T Developer W Maximum width θ Repose angle of developer

Claims (11)

A developer carrier rotatably provided in proximity to or in contact with the image carrier, a developer supply member rotatably provided to supply a developer as powder on the developer carrier, A developer supply chamber having a developer stirring member provided in a non-contact and rotatable manner with respect to the developer carrier and the developer supply member above the developer supply member;
A developer storage chamber disposed above the developer supply chamber to store the developer, and having a rotatable agitator that stirs the developer; and
A layer regulating member that contacts the developer carrier and thins the developer on the developer carrier;
In the developing device for developing the electrostatic latent image formed on the image carrier by applying a predetermined voltage to the developer carrier,
One or more developer transport auxiliary chambers for adjusting the transport amount of the developer are provided between the developer storage chamber and the developer supply chamber,
Boundary walls between the developer storage chamber, the developer conveyance auxiliary chamber, and the developer conveyance auxiliary chamber and the developer supply chamber each have a supply port through which the developer can be conveyed,
A boundary wall that separates the developer conveyance auxiliary chamber and the developer supply chamber is formed of a flexible sheet-like member, and is regularly arranged with the developer agitating member disposed in the developer supply chamber. A developing device arranged so as to be in contact with each other . The supply port of the boundary wall separating the developer conveying auxiliary chamber and said developer supply chamber, in the lower portion of the developer transport auxiliary chamber, according to claim 1, wherein it has been found disposed in a vertically Development device. The supply port of the boundary wall that separates the developer conveyance auxiliary chamber and the developer supply chamber is provided on the side surface side of the developer conveyance auxiliary chamber that is the direction of the force applied by the rotation of the developer stirring member. The developing device according to claim 1 . The angle of repose of the developer measured with a measuring device is θ, the maximum width of the cross section perpendicular to the longitudinal direction of the developer conveyance auxiliary chamber is w, and the position that forms the maximum width w is from the bottom of the developer conveyance auxiliary chamber. when the height was is h, the developing device according to any one of claims 1 to 3 and satisfies the w × tanθ = 4h. The supply port of the boundary wall which separates the developer accommodating chamber and said developer transport assisting chamber, to any one of claims 1 to 4, characterized in that is not provided at the top of the developer transport auxiliary chamber The developing device described. The supply port of the boundary wall which separates the developer accommodating chamber and said developer conveying auxiliary chamber, any one of claims 1 to 5, characterized in that provided below the center of rotation of the agitator The developing device according to 1. The supply port of the boundary wall which separates the developer accommodating chamber and said developer conveying auxiliary chamber, any one of claims 1 to 6, characterized in that provided above the lowermost position of the agitator The developing device according to item . An apparatus according to any one of claims 1 to 7, characterized in that arranged rotatably auxiliary chamber developer stirring member for stirring the developer inside the developer conveying auxiliary chamber. The auxiliary chamber developer agitating member is disposed in the developer conveyance auxiliary chamber so as to periodically contact and press a boundary wall separating the developer conveyance auxiliary chamber and the developer supply chamber. The developing device according to claim 8 . A process cartridge that includes at least an image carrier and a developing device, and is detachable from an image forming apparatus main body ;
10. A process cartridge comprising the developing device according to claim 1 as the developing device . An image forming apparatus comprising the process cartridge according to claim 10 .

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