JP2010032648A - Developing device, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device having a new constitution which is simple but surely prevents the adhesion of a developer to an inner surface of a developing tank or a conveying member caused by the flocculation of the developer to achieve the stable supply of the developer, and surely prevents a harmful effect such as the unevenness of image density. <P>SOLUTION: A developer supply part 3B has a space in which a developer carrier 3B1 carrying the developer on its surface while it opposes a latent image carrier, a developer supply member 3B2 supplying the developer toward the developer carrier 3B1, and a developer stirring member 3B3 uniformly diffusing and conveying the developer are arranged, wherein the developer stirring member 3B3 is constituted of a rotatable screw auger, provided with a flexible coil 20 wound round the outer peripheral surface of the rotary shaft 3B30 of the screw auger, and vibrates in a shaft direction of the rotary shaft 3B30 by the elongation/contraction of the coil by a frictional force generated when contacting with the developer generated during rotation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developing device, a process cartridge, and an image forming apparatus, and more particularly to a configuration for preventing supply failure due to toner condensation.

  In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a printing machine using an electrophotographic system, an electrostatic latent image formed on a photosensitive member that is a latent image carrier is visible by toner supplied from a developing device. Image processing is performed.

In addition to the method of forming a single color image using a single latent image carrier, the image forming apparatus includes a latent image carrier and a charging device that performs image forming processing on the latent image carrier for each color, There is a system that includes a developing device and a cleaning device, and superimposes and transfers a color image formed in each image forming unit onto an intermediate transfer member or a transfer material that moves through each image forming unit.
As a typical example of the latter system, a tandem system in which the respective image forming units are juxtaposed along the belt extending direction used as an intermediate transfer member or a transfer material conveying member is generally known.

  The developing device disposed in each image forming unit includes a developing sleeve that contacts the developer carried on the surface with the latent image carrier, a supply member that supplies the developer to the developing sleeve, and the developing sleeve and the supply. A stirring member for stirring the developer contained in the developing tank in which the member is disposed is provided.

  When a shortage of toner occurs in the developing tank, the toner is supplied from a toner replenishing tank disposed above the developing tank so that the developer concentration in the developing tank is maintained constant. .

  By the way, the developer is accommodated in the developing tank, stirred by the stirring member, and frictionally charged at the time of stirring to set predetermined charging characteristics. However, depending on the amount of developer and the length of the storage period, the developer is deposited. Condensation of the developing developer may occur, and the smooth fluidity of the developer may be impaired, resulting in poor supply.

  In particular, when the stirring member is stopped in a state where the remaining amount of the developer is large, the developer is pressed and hardened due to the weight of the developer and is likely to condense.

  Condensation of the developer not only impairs the fluidity but also causes adhesion of the surface of the member used as the developer conveying member and the inner wall surface of the developer accommodating portion, so that the developer staying in part There is a possibility that the charging characteristics of the member deteriorate, and the load on the drive source of the member increases.

  In particular, when using a one-component developer that does not contain a carrier instead of a two-component developer that requires mixing and stirring for frictional charging of the toner, the developer is different from the two-component developer. Therefore, the above-mentioned problems are likely to occur. In other words, in the case of a one-component developer, the toner is triboelectrically charged when rubbed against the developing sleeve or when it collides with the layer thickness regulating member, so an operation such as stirring and mixing is necessary. And not. For this reason, the above-described condensation is likely to occur by continuing the developer accumulation state by not always stirring and mixing.

  The cause of condensation of the toner used in the developer is to enable oilless fixing (fixing that uses as little as possible a release agent for preventing offset) or low-temperature fixing that has recently been used. There is toner containing wax. Such toners are relatively soft and have high adhesion between the toners due to viscosity and the like, so that they easily condense, and condensing problems become conspicuous when these functional toners are used.

  When the developer condenses in the developing device, the developer easily adheres to the inner surface of the developing tank or the surface of the conveying member, and the adhering developer, particularly the toner, causes a frictional charging failure or the mass of the conveying member. This increases drive torque.

  Therefore, conventionally, in order to avoid the storage of a large amount of developer that causes such condensation, the developing tank and the toner replenishing tank that stores the replenishing toner are separated, and the toner is supplied to the developing tank only during replenishment. A configuration in which the supply is performed (for example, Patent Document 1), or a configuration in which the developing sleeve and the supply roller are juxtaposed in the horizontal direction so that the developer that contacts these members is not condensed by gravity (for example, a patent) Document 2), and further, an elastic member that contacts the surface of the conveying member disposed in the developing tank is provided so that the developer attached to the surface of the conveying member is repelled and removed (for example, Patent Document 3). In addition, there is a configuration in which the shape of a blade member used as a conveying member in order to prevent the developer from adhering to the conveying member is an ellipse or a half moon (for example, Patent Document 4).

Japanese Patent Laid-Open No. 10-20640 JP-A-2005-148446 JP-A-5-224562 JP 2001-42623 A

  In the configuration in which the developing tank and the toner replenishing tank are separated or the developing sleeve and the supply member are juxtaposed in the horizontal direction, there is still a possibility that condensation may occur depending on the amount of developer remaining in the developing tank. In the configuration in which the developer adhered to the surface of the conveying member is removed by the elastic member, an increase in driving torque due to the contact of the elastic member cannot be denied, and when the shape of the conveying member is changed, the normal conveying amount is increased. There is a risk that it cannot be secured.

  In any case, the present situation is that the simple configuration does not reliably prevent the developer from condensing to prevent uneven image density caused by unstable supply.

  Therefore, in view of the problems in the conventional developing device, the present invention reliably prevents the developer from condensing on the inner surface of the developing tank and the conveying member due to the condensation of the developer, and enables a stable supply of the developer. An object of the present invention is to provide a developing device having a novel configuration capable of reliably preventing adverse effects such as image density unevenness, a process cartridge and an image forming apparatus using the developing device.

In order to achieve this object, the present invention has the following configuration.
(1) A developing device used for visible image processing of an electrostatic latent image formed on a latent image carrier,
A developer having a space in which a developer carrier that carries a developer on the surface thereof facing the latent image carrier and a developer supply member that supplies the developer toward the developer carrier A supply section;
A developer container that is connected to the developer supply part via a partition part and is capable of circulating the developer housed through a communication part provided in the partition part;
A developer agitating member that is provided in the developer supply unit and conveys the developer contained therein while stirring so as to uniformly disperse the developer;
The developer agitating member is composed of a rotatable screw auger, and an expandable coil is loaded on the outer peripheral surface of the rotation axis of the screw auger, and a frictional force generated upon contact with the developer generated at the time of rotation. The developing device is characterized in that the coil vibrates in the axial direction of the rotating shaft by expanding and contracting the coil.
(2) The developing device according to (1), wherein the coil is loaded with a gap provided between the outer surface of the rotary shaft of the screw auger.
(3) The coil contracts and deforms in accordance with the rotation of the screw auger, and a reduced diameter state due to the contraction deformation collides with a protrusion disposed on the inner surface of the developer supply unit corresponding to the end in the axial direction. The developing device according to (1) or (2), wherein when the diameter is expanded, the contracted state returns to the extended state.
(4) The developing device according to (3), wherein the protrusion includes an inclined surface on which an inner surface of an end of the coil can ride.
(5) The developing device according to any one of (1) to (4), wherein the screw auger is rotatable forward and backward.
(6) A developing device used for visible image processing of an electrostatic latent image formed on a latent image carrier,
A developer having a space in which a developer carrier that carries a developer on the surface thereof facing the latent image carrier and a developer supply member that supplies the developer toward the developer carrier A supply section;
A developer container that is connected to the developer supply part via a partition part and is capable of circulating the developer housed through a communication part provided in the partition part;
A developer agitating member comprising a screw auger that is provided in the developer supply unit and agitates and conveys the developer contained therein so as to be uniformly dispersed, and a coil that is loaded on the outer peripheral surface of the rotating shaft of the screw auger And
A plurality of communication portions provided in the partition portion are provided in the axial direction of the screw auger, and at least one is provided in the axial center of the screw auger,
The developing device according to claim 1, wherein the coil is mounted in different directions with the axial center of the screw auger as a boundary.
(7) The developing device according to (6), wherein the coil is connected in the center in the axial direction of the screw auger.
(8) The developing device according to any one of (1) to (3), 6 or 7, wherein the coil is made of a shape memory alloy.
(9) A process comprising: the developing device according to any one of (1) to (8); and a housing that collectively stores a latent image carrier that carries at least an electrostatic latent image to be developed. cartridge.
(10) An image forming apparatus using the process cartridge according to (9).

  According to the present invention, since the coil that can be expanded and contracted is provided on the outer peripheral surface of the rotating shaft of the screw auger used as the developer supplying and conveying member disposed in the developer supplying section, the coil rotates in conjunction with the screw auger. When contracted by the reaction force from the developer that is received, the diameter is reduced, and when the reduced diameter state is released, the diameter is expanded and the original state is restored. Therefore, vibration can be caused by repeating expansion and contraction of the coil. Thereby, it is possible to suppress the occurrence of adhesion due to the developer adhering to the inner surface of the developer supply unit or the member used for stirring and conveying the developer being peeled off by the vibration of the coil. As a result, the developer condensation is eliminated, and the developer supply failure can be eliminated.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a view showing an image forming apparatus using a developing device according to the present invention. The image forming apparatus shown in FIG. 1 is an image forming unit for each color (in FIG. 1, reference numerals Y, C, M, A tandem system is used in which the color classification is indicated by K) along the direction of extension of a transfer belt used as an intermediate transfer member.

In FIG. 1, the image forming apparatus has the same configuration in each image forming unit. As a representative example, the configuration will be described for black (image forming unit indicated by symbol K in FIG. 1). It is as follows.
The image forming unit K is provided with a drum-shaped photosensitive member 1 that is a latent image carrier so as to be rotatable. An image forming process is performed around the photosensitive member 1 along the rotation direction of the photosensitive member 1. A charging device 2, a developing device 3, and a cleaning device 4 are arranged for carrying out the processing. These devices are housed in a process cartridge 5 together with a photosensitive member.

  When the photoreceptor 1 is uniformly charged with a predetermined polarity through a predetermined bias by the charging device 2, an electrostatic latent image corresponding to image information is formed using the writing device 6, and the electrostatic latent image is A visible image is processed by the developer supplied from the developing device 3 to form a toner image.

The toner image is transferred to the transfer belt 7A by the primary transfer device 8 facing the photoconductor 1 with the transfer belt 7A provided in the intermediate transfer device 7 interposed therebetween.
The processing up to the primary transfer process using the primary transfer device 8 is performed in the same manner in each image forming unit when a plurality of color images are formed, and the toner image carried on the photoreceptor 1 is transferred to the transfer belt 7A. Are sequentially transferred and superimposed with the movement of.
The superimposed images sequentially transferred onto the transfer belt 7A are collectively transferred to the transfer material S fed from a paper feeding device (not shown) via the secondary transfer device 9, and the transferred transfer material S is fixed. The toner image is fixed by being conveyed to the apparatus 10.
Residual toner is removed from the photoreceptor 1 and the transfer belt 7A after the transfer by the cleaning devices 4 and 11.

  FIG. 2 is an enlarged view of the process cartridge 5 for a black (K) image. In FIG. 2, the developing device 3 is intended for a configuration using a one-component developer, and contains replenishing toner. A replenishing toner tank 3A corresponding to the developer accommodating portion and a developing tank 3B corresponding to a developer supplying portion which is disposed below the replenishing toner tank 3A and supplies the developer to the photosensitive member 1 are provided.

  A replenishing toner tank 3A (hereinafter sometimes referred to as a replenishing toner tank) that is a developer container and a developing tank 3B (hereinafter also referred to as a developing tank) that is a developer supply section are a partition portion 3C. The partition portion 3C is formed with a plurality of communication portions 3C1 along a direction perpendicular to the paper surface shown in FIG.

  Inside the replenishing toner tank 3A, a developer conveying member 3A1 using a screw auger is rotatably disposed in the vicinity of the communicating part 3C1 in the partition part 3C. The developer conveying member 3A1 is not shown, but the developing tank When the developer concentration is lowered by a signal from a sensor for detecting the developer concentration in 3B, the rotation is started and the toner is replenished from the replenishment toner tank 3A. The developer conveying member 3A1 is not limited to a screw auger, but a developer having a conveying function such as a conveying belt or a coiled rotating body, or a paddle formed by bending a plate member such as a blade or a wire. A combination of those having a stirring function such as the above may be used. Further, the developer may be transported in the normal direction with respect to the rotation arc of the developer transport member 3A1.

  Inside the developing tank 3B, a developing sleeve 3B1 as a developer carrying body that carries the developer on the surface thereof facing the photoreceptor 1, and development for supplying the developer in the developing tank 3B to the developing sleeve 3B1 The developer supply member 3B2, the developer agitating member 3B3 for uniformly diffusing the toner from the replenishing toner tank 3A in the developing tank 3B, and the layer thickness of the developer carried on the developer carrier 3B1 are defined. And a sealing member 3B5 which is disposed in the vicinity of the developing sleeve 3B1 and prevents leakage of the developer from the inside of the developing tank 3B.

The developing sleeve 3B1 uses a roller coated with an elastic rubber layer, and a surface coat layer made of a material that is easily charged to a polarity opposite to that of the developer is provided on the surface.
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 member 1 uniform, and further has an electric resistance of about 10 ³ to 10 ¹⁰ Ω in order to act a developing bias. Value is set. Furthermore, the surface roughness Ra is set to 0.2 to 2.0 μm, and a necessary amount of developer is held on the surface. The developing sleeve 3B1 rotates counterclockwise in FIG. 2, and conveys the developer held on the surface to a position facing the layer regulating member 3B4 and the photosensitive drum 2.

The developer supply member 3B2 is a roller coated with a foam material having a structure having pores (cells) on the surface thereof, and the developer introduced into the developer tank 3B is efficiently attached and taken in, and a developing sleeve The toner deterioration due to the pressure concentration at the contact portion with 3B1 is prevented. The foamed material described above is set to an electrical resistance value of 10 ³ to 10 ¹⁴ Ω.
The developer supply member 3B2 is applied with an offset voltage as a supply bias having the same polarity as the developer charging polarity with respect to the potential applied to the developing sleeve 3B1. This supply bias acts in a direction in which the precharged developer is pressed against the developing sleeve 3B1 at the contact portion with the developing sleeve 3B1. However, the polarity of the voltage applied to the developer supply member 3B2 is not limited to this, and the same potential or polarity as that of the developing sleeve 3B1 may be reversed depending on the type of the developer.

  The developer supply member 3B2 rotates in the counterclockwise direction in FIG. 2, and the developer attached to the surface is applied and supplied to the surface of the developing sleeve 3B1.

  The layer thickness regulating member 3B4 is made of a metal leaf spring material such as SUS304CSP, SUS301CSP, or phosphor bronze, and the free end is brought into contact with the surface of the developing sleeve 3B1 with a pressing force of 10 to 100 N / m. The developer that has passed through the position where the pressure acts is thinned and an electric charge is applied by triboelectric charging. Further, a voltage that is offset to the same polarity as the developer charging polarity with respect to the potential applied to the developing sleeve 3B1 is applied to the layer thickness regulating member 3B4 as a regulating bias in order to assist frictional charging.

  In the developing device 3, the developing sleeve 3 </ b> B <b> 1 is set to rotate in the same direction at the position facing the photoreceptor 1, and is rotated so that the layer thickness is regulated on the surface of the developing sleeve 3 </ b> B <b> 1. The developed developer is conveyed to a position facing the photoreceptor 1, and the developer is in accordance with the developing bias applied to the developing sleeve 3 </ b> B <b> 1 and the latent image electric field in the electrostatic latent image on the photoreceptor 1. Is electrostatically adsorbed onto the electrostatic latent image.

  FIG. 3 is a cross-sectional view showing the configuration in the vicinity of the partition portion 3C in the developing device 3 from the front. In FIG. 3, a replenishment toner tank 3A as a developer containing portion is interposed above the partition portion 3C. A developing tank 3B as a developer supply unit is located at the lower part.

  In FIG. 3, the developer agitating member 3B3 disposed in the developing tank 3B is composed of a screw auger (hereinafter sometimes referred to as a screw auger 3B3), and depending on its lead direction (spiral direction). The developer introduced into the developing tank 3B from one of the communicating parts 3C1 formed in the partition part 3C is conveyed while being stirred in the developing tank 3B, and the developer is supplied from the other of the communicating parts 3C1 to the replenishing toner tank 3A. It is designed to recirculate towards the. In the communication portion 3C1 provided at a position where the developer circulates from the other side of the communication portion 3C1, that is, from the developer tank 3B side to the replenishment toner tank 3A, the developer is gathered and swollen by the rotation of the developer stirring member 3B3. Therefore, the developer on the replenishment toner tank 3A side is prevented from dropping, and the developer amount in the developer tank 3B is always optimized. .

On the other hand, a coil 20 is mounted on the rotating shaft 3B30 of the developer stirring member (screw auger) 3B3.
The coil 20 is made of a deformable resin or a shape memory alloy, and is inserted with a gap between the outer peripheral surface of the rotary shaft 3B30. When the rotary shaft 3B30 rotates, a reaction force from the developer is generated. When it is tightened by receiving, it comes into pressure contact with the rotating shaft 3B30, and in this state, it moves according to the movement of the developer.

  Since the present embodiment is configured as described above, when the developer agitating member (screw auger) 3B3 rotates in the developing tank 3B, the developer is brought into contact with the developer contained in the developing tank 3B. The reaction force causes the coil 20 to move toward the downstream side in the developer moving direction due to the rotation of the developer stirring member (screw auger) 3B3. The contraction of the coil 20 causes the diameter of the coil 20 to be reduced. As a result, the developer stirring member (screw auger) 3B3 is wound around the rotation shaft 3B30. In this state, when the front end of the coil 20 in the moving direction comes into contact with the inner surface of the developing tank 3B, the coil that has been moved while contracting is prevented from moving. For this reason, the coil 20 can be restored to its original stretched state by loosening from the tightened state when the end portion is pressed, and then expanding. Thereby, it vibrates by repeating shrinkage | contraction and expansion | extension, a vibration is transmitted to the surface of stirring member 3B4, and the developer adhering to the surface by condensation can be peeled off.

  The diameter-expansion operation at the time of changing from the contracted state to the extended state is not limited to the collision with the inner surface of the developing tank 3B, but a projection 21 provided on the inner surface of the developing tank 3B can be used as shown in FIG. That is, in FIG. 4, the protrusion 21 includes an inclined surface 21A on which the inner surface of the end portion of the coil 20 that moves with the rotation of the developer stirring member (screw auger) 3B3 can run on in the lead direction. When the part inner surface rides on, the diameter can be changed from the reduced diameter to the enlarged diameter.

  FIG. 5 shows a configuration in which protrusions 21 are provided in the directions in which the developer agitating member (screw auger) 3B3 moves in accordance with forward and reverse rotation.

  On the other hand, as a configuration for promoting the movement of the coil accompanying the rotation of the developer stirring member (screw auger) 3B3, a configuration in which a weir plate 22 is provided at the end of the coil 20 as shown in FIG. That is, when the coil 20 rotates with the rotation of the developer agitating member (screw auger) 3B3, the barrier plate 22 can easily receive the reaction force from the developer, and thereby the coil 20 can be smoothly contracted. Can be

  6 corresponds to the case where the rotation shaft 3B30 capable of forward / reverse rotation, which is the same reason as that of the protrusion 21 shown in FIG. 5, is used, the relative position with the rotation center in the circumferential direction of the rotation shaft 3B20. The structure where the dam plate 22 is provided is shown.

  The reason why the rotating shaft 3B30 is rotated forward and backward is to avoid noise caused by continuing the sound when the coil 20 collides with and contacts the inner surface of the developing tank 3B or the protrusion 21. That is, if the reduced diameter state of the coil is changed to the enlarged state, the coil 20 returns to the original state. Therefore, if the rotation of the rotary shaft 3B30 is changed when the diameter is changed to the enlarged state. Further, it is possible to prevent the generation of noise due to the continuation of the abutting state against the inner surface of the developing tank 3B and the generation of sliding noise when riding on the inclined surface 21A of the protrusion 21.

  Further, instead of the barrier plate 22, as shown in FIG. 7, a weight 23 is provided so that the coil 20 tends to be slack in the normal state and to be tightened as the developer stirring member (screw auger) 3B3 rotates. It can be contracted and moved. Since the weight 23 can also have the function of the barrier plate 22, the movement of the coil 20 when contracted can be speeded up.

Next, another embodiment of the present invention will be described.
FIG. 8 is a view corresponding to FIG. 3 for explaining another embodiment of the present invention, and is different from the structure shown in FIG. 3 in that the communication portion provided in the partition portion 3C and the developer stirring member (screw auger). 3B3, and a coil (denoted by reference numeral 20 'for convenience).

  The communicating portions provided in the partition portion 3C are formed at the axial center of the developer agitating member (screw auger) 3B3 and at the end portions that are equal to each other with reference to the center (indicated by reference numerals 3C1 and 3C1 ′). ).

  On the other hand, the developer agitating member (screw auger) 3B3 and the developer conveying member 3A1 located in the replenishing toner tank 3A are different in the axial direction center of the rotation axis of these members, and in the opposite directions in the figure. The lead direction (spiral direction) is set. The opposite directions in this case are the communicating portions 3C1 located on both sides of the communicating portion where the developer in the replenishing toner tank 3A and the developing tank 3B is provided in the partition portion 3C with the center in the axial direction as a boundary. It corresponds to the direction of moving toward.

  The developer agitating member (screw auger) 3B3 located on the developing tank 3B side is equipped with a coil 20 'similar to the configuration shown in FIG. 3, and the coil 20' is connected to the developer agitating member (screw auger). ) Similar to 3B3, the lead direction (spiral direction) is set in a direction opposite to the center in the axial direction. Then, as shown in FIG. 9, at the center in the axial direction of the developer agitating member (screw auger) 3B3, as shown in FIG. 9, the locking pins 3B31 provided at the ends of the rotating shaft 3B30 of the developer agitating member (screw auger) 3B3. The end of the coil 20 'is engaged with the coil.

In the present embodiment, when the developer agitating member (screw auger) 3B3 rotates, the developer in the developing tank 3B becomes half the axial length with respect to the axial center of the developer agitating member (screw auger) 3B3. Are respectively transported in the area.
Among the communicating parts provided in the partition part 3C, the developer is supplied from the replenishing toner tank 3A into the developing tank 3B via a communicating part 3C1 'located in the axial center of the developer agitating member (screw auger) 3B3. When introduced, the developer tank 3B is transported toward the axial side in the half region in the axial direction, and from the communicating portion 3C1 positioned on the axial side of the developer agitating member (screw auger) 3B3. It is recirculated toward the replenishment toner tank 3A.

  On the other hand, the coil 20 ′ vibrates in a region that is half the axial length from the center in the axial direction of the developer stirring member (screw auger) 3 B 3 and adheres to the surface of the developer stirring member (screw auger) 3 B 3. The developing agent can be peeled off.

  In the present embodiment, since the developer introduced from the axial center with respect to the axial center of the developer agitating member (screw auger) 3B3 can be transported in a region half the axial length, respectively. Compared with the case where the developer is transported from one end side in the axial direction to the other end side, the developer can be uniformly distributed. Further, in the replacement of the coil 20, when one of them is replaced at the center in the axial direction, Since it is not necessary to replace up to the other half of the coil, the maintenance cost can be reduced.

1 is a schematic diagram of an image forming apparatus using a developing device and a process cartridge according to the present invention. FIG. 2 is a schematic diagram illustrating a configuration of a process cartridge in the image forming apparatus illustrated in FIG. 1. FIG. 3 is a cross-sectional view of the developing device housed in the process cartridge shown in FIG. 2 as viewed from the front. It is a figure which shows the principal part structure of the image development apparatus by this invention. It is a figure which shows a partial modification to the principal part structure shown in FIG. It is a figure which shows the modification which carries out the main part structure daily publication shown in FIG. It is a figure which shows the modification of the principal part structure shown in FIG. FIG. 4 is a view corresponding to FIG. 3 for explaining another embodiment relating to the developing device according to the present invention. It is a figure which shows the principal part of embodiment shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 3 Developing apparatus 3A Supply toner insertion 3A1 Developer conveyance member 3B Developer tank 3B3 Screw auger 3B30 Rotating shaft 3B31 Locking pin 3C Partition part 3C1, 3C1 'Communication part 5 Process cartridge 20, 20 'Coil 21 Projection 21A Inclined surface 22 Dam plate 23 Weight

Claims (10)

A developing device used for visible image processing of an electrostatic latent image formed on a latent image carrier,
A developer having a space in which a developer carrier that carries a developer on the surface thereof facing the latent image carrier and a developer supply member that supplies the developer toward the developer carrier A supply section;
A developer container that is connected to the developer supply part via a partition part and is capable of circulating the developer housed through a communication part provided in the partition part;
A developer agitating member that is provided in the developer supply unit and conveys the developer contained therein while stirring so as to uniformly disperse the developer;
The developer agitating member is composed of a rotatable screw auger, and an expandable coil is loaded on the outer peripheral surface of the rotation axis of the screw auger, and a frictional force generated upon contact with the developer generated at the time of rotation. The developing device is characterized in that the coil vibrates in the axial direction of the rotating shaft by expanding and contracting the coil.   The developing device according to claim 1, wherein the coil is loaded with a gap provided between the outer surface of the rotary shaft of the screw auger.   The coil contracts and deforms in accordance with the rotation of the screw auger, and a contracted state due to the contraction deformation collides with a protrusion disposed on the inner surface of the developer supply unit corresponding to the end in the axial direction. The developing device according to claim 1, wherein the developing device is configured to return from a contracted state to an expanded state when the diameter is increased.   The developing device according to claim 3, wherein the protrusion includes an inclined surface on which an inner surface of an end of the coil can run.   The developing device according to claim 1, wherein the screw auger can be rotated forward and backward. A developing device used for visible image processing of an electrostatic latent image formed on a latent image carrier,
A developer having a space in which a developer carrier that carries a developer on the surface thereof facing the latent image carrier and a developer supply member that supplies the developer toward the developer carrier A supply section;
A developer container that is connected to the developer supply part via a partition part and is capable of circulating the developer housed through a communication part provided in the partition part;
A developer agitating member comprising a screw auger that is provided in the developer supply unit and diffuses and conveys the developer contained therein so as to be uniformly dispersed, and a coil that is loaded on the outer peripheral surface of the rotating shaft of the screw auger And
A plurality of communication portions provided in the partition portion are provided in the axial direction of the screw auger, and at least one is provided in the axial center of the screw auger,
The developing device according to claim 1, wherein the coil is mounted in different directions with the axial center of the screw auger as a boundary.   The developing device according to claim 6, wherein the coil is connected in the center in the axial direction of the screw auger.   The developing device according to claim 1, wherein the coil is made of a shape memory alloy.   9. A process cartridge comprising: the developing device according to claim 1; and a housing that collectively stores a latent image carrier that carries at least an electrostatic latent image to be developed.   An image forming apparatus using the process cartridge according to claim 9.

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