JP2008185846A - Development device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development device where deterioration in a two component developing agent on a developing agent carrier is suppressed, a developing agent layer can be stably formed into a thin layer, and a high quality image can be stably obtained over a long term, to provide a process cartridge using the development device, and to provide an image forming apparatus. <P>SOLUTION: The development device includes: a fixed magnetism generating means for generating a plurality of magnetic fields; a developing agent carrier composed of a sleeve surrounding the fixed magnetism generating means; and a developing agent regulation member for regulating the pressure of the developing agent layer on the developing agent carrier. The passage for feeding the developing agent onto the developing agent carrier includes a feed adjustment means for the developing agent, and the feed adjustment means includes an adjustment means for performing adjustment in such a manner that the amount of the developing agent held onto the developing agent carrier member before the adjustment of the developing agent reaches ≤2 times the amount of the developing agent after the passage of the developing agent regulation means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a developing device used in a copying machine, a facsimile machine, a printer, and the like, and a process cartridge and an image forming apparatus using the developing device. More specifically, a latent image carried on a latent image carrier is transferred to a toner and a carrier. The present invention relates to an invention of a developing device for developing with a two-component developer containing

2. Description of the Related Art Conventionally, developing devices using a two-component developer composed of a carrier and a toner are known. In the developing device using the two-component developer, the developer is carried on a developer carrier as a so-called magnetic brush, the developer is regulated to a predetermined thickness, and the electrostatic image on the latent image carrier such as a photoconductor is regulated. It is common practice to develop a latent image.
As the developer carrying member, for example, a cylindrical developing sleeve that is rotatably arranged and carries and conveys a two-component developer, and a magnet roll that is fixedly arranged in the developing sleeve and has a plurality of magnetic poles arranged around it. And.
In order to faithfully develop the electrostatic latent image on the latent image carrier, it is necessary to reduce the distance between the latent image carrier and the developer carrier. As the distance between the latent image carrier and the developer carrier decreases, the developer layer formed on the developer carrier needs to be formed in a thinner layer. In order to adjust the thickness of such a thin layer, for example, there is a method of regulating the thickness of the developer layer on the developer carrying member. As such a technique, a system in which a developer regulating member is disposed in a non-contact manner with a predetermined gap (hereinafter referred to as a doctor gap) with respect to the developer carrying member is widely adopted. In this system, the amount of developer passing through the developer regulating member can be adjusted by controlling the doctor gap, but in order to form a thin layer, the doctor gap needs to be set very small.
However, if the doctor gap is set small, the amount of developer passing through the doctor gap becomes larger than when the doctor gap is set large, and the developer layer formed on the developer carrier becomes non-uniform. There is. Further, when the developer passes through the doctor gap, a great stress is applied to the developer, and there is a problem that the life of the developer is shortened.
In order to solve such a problem, in the conventional developing device, magnetic poles of the same polarity are arranged adjacent to each other on the magnet roll of the developer carrying member, and the maximum magnetic position of the magnetic pole upstream in the developer transport direction and the minimum between these magnetic poles A developer regulating member is provided between the magnetic positions. Thereby, the packing density of the developer in the doctor gap is lowered, and the amount of developer passing through the doctor gap can be reduced. In addition, the developer passing through the doctor gap is hardly affected by the force to pass through the doctor gap other than the rotational force of the developing sleeve. For this reason, even if the doctor gap is set small, the variation in the amount of developer passing through the doctor gap is small, and a thin uniform layer can be formed on the developing roller (see, for example, Patent Documents 1 and 2).
JP-A-5-6103 JP 2005-275069 A

However, since the developing device described in Patent Document 1 has a strong repulsive force between magnetic poles of the same polarity, the developer conveying force for allowing the doctor gap to pass is too low. As a result, when the characteristics of the developer fluctuate due to environmental fluctuations or the like, there is a problem that the developer conveyance amount is likely to fluctuate and the developer layer formation becomes unstable.
Further, the developer accumulation amount regulated by the developer regulating member is deposited before the developer regulating member to be in a high packing state, and a shearing force or a pressing force is continuously applied to the toner. When the toner is in a high packing state, the external additive on the toner surface is easily detached or embedded in the toner, and the external additive coverage of the toner is reduced. When the coverage of the external additive on the toner is reduced, the adhesion between the carrier and the toner becomes strong and the toner becomes difficult to separate, so that the developability is lowered.
The present invention has been made in view of the above-described problems, and the amount of developer accumulation regulated by the developer regulating member is not more than twice the amount of developer passing through the developer regulating member. To regulate. As a result, the relative amount of the developer that receives a force from the developer regulating member in the total amount of the developer is reduced, and the degree of deterioration of the developer is reduced.
In other words, the present invention is a developing device that can suppress deterioration of the two-component developer on the developer carrying member, stably form the developer layer into a thin layer, and obtain a stable high-quality image over a long period of time. And a process cartridge and an image forming apparatus using the developing device.

In order to solve the above-described problems, the invention described in claim 1 is directed to a fixed magnetism generating means for generating a plurality of magnetic fields, a developer carrier comprising a sleeve that circulates the fixed magnetism generating means, and the developer. A developing device including a developer regulating member that regulates a developer layer pressure on a carrier, wherein a developer supply amount adjusting means is provided on a path for supplying the developer on the developer carrier, and the supply amount is adjusted. The adjusting means adjusts so that the amount of developer held on the developer carrying member before adjusting the developer is not more than twice the amount of developer after passing through the developer regulating member. A developing device having the following features.
According to a second aspect of the present invention, the supply amount adjusting means controls a conveyance amount of a mixing and agitating unit that agitates a developer component containing at least one selected from toner, a carrier, and a circulating developer. The developing device according to claim 1, wherein the developer is supplied onto the developer carrier from a supply port.
According to a third aspect of the present invention, there is provided the developing device according to the first or second aspect, wherein the developer supplied before the developer regulating member is at least partially charged before reaching the developer regulating member. Features.
According to a fourth aspect of the invention, there is provided the developing device according to the second or third aspect, wherein the supply amount adjusting means adjusts by changing an opening area of the supply port.
According to a fifth aspect of the invention, the supply amount adjusting means adjusts the supply amount of the developer according to an output signal of a difference before and after passing through the developer regulating member by a sensor. A developing device according to any one of the above.
The invention described in claim 6 is configured such that at least one selected from a latent image carrier, a charging unit, and a cleaning unit and the developing unit are integrated with the image forming apparatus main body. It is a process cartridge, Comprising: The said developing means is characterized by the process cartridge which is a developing device as described in any one of Claims 1 thru | or 5.
According to a seventh aspect of the invention, there is provided an image forming apparatus including the developing device according to any one of the first to fifth aspects or the process cartridge according to the sixth aspect.

  According to the present invention, a fixed magnetism generating means for generating a plurality of magnetic fields, a developer carrying member comprising a sleeve rotating around it, and a developer regulating member for regulating the developer layer pressure on the developer carrying member A developer supply amount adjusting means provided in a path for supplying the developer onto the developer carrier, and the amount of developer held on the developer carrier member before adjustment is And a developing device characterized by having an adjusting means for adjusting the amount to be not more than twice the amount of developer after passing through the developer regulating member. It is possible to provide a developing device that can suppress deterioration of the two-component developer on the body, stably form the developer layer into a thin layer, and obtain a stable high-quality image over a long period of time. In addition, it is possible to provide a process cartridge and an image forming apparatus using the developing device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows the configuration of the developing device according to the present invention.
Although details will be described later, when the developer 10 is transported to the electrostatic image carrier 1 by a developer carrier having a magnetic field generating means, excessive shearing force or pressing force is generated before and after the developer regulating member 12. This is prevented. As a result, the toner is in a high-packing state and the external additive on the toner surface is easily detached or embedded in the toner, the external additive coverage of the toner is reduced, and the external additive coating on the toner When the rate is reduced, the adhesion between the carrier and the toner becomes strong, thereby preventing the developability from being lowered. That is, according to the present invention, the amount of developer deposited regulated by the developer regulating member is regulated to be not more than twice the amount of developer passing through the developer regulating member. Since the relative amount of the developer that receives a force from the developer regulating member out of the total amount is reduced, the degree of deterioration of the developer can be reduced.
The amount of developer held by the magnetic field generating means at the opposite side of the developer regulating member on the upstream side of the developer carrying member with respect to the developer carrying member relative to the developer regulating member is determined by the developer regulating member on the developer carrying member. This is the amount of developer carried from the facing position to the position where the magnetic force density distribution value in the normal direction of the magnetic field generating means becomes zero.

In this developing apparatus, the agent regulating member (developer regulating member) has a function of regulating the amount of the developer present on the developer carrier so as not to exceed a certain level. Do not do. Therefore, since it is necessary for the developer to rise before passing through the agent regulating member, the toner can be sufficiently obtained by providing a mechanism for charging from the outside in the stirring unit or improving the fluidity of the supplied toner. The developer is supplied to the developer carrying member. For example, in order to assist charging, the inner surface of the developer supply unit 13 is subjected to a roughening process in order to promote contact charging between the developer carrier and the toner stirred by the stirring member 11. This makes it possible to effectively use the air flow slightly generated by the stirring of the stirring member for charging the developer, and to prevent the developer from being pressed by the air flow.
Further, for example, the flowability of the developer is increased by increasing the stirring efficiency of the toner including the external additive with the external additive.
The developer regulating member has a supply port disposed on a surface facing the developer carrier on the upstream side of the developer carrier in the developer transport direction, and the developer is supplied through the supply port. By adjusting the opening area so that the developer having the same amount as the amount of developer passing therethrough can be adjusted, the amount of developer deposited before the regulating member can be made twice or less the amount of passage.
Moreover, since the agent is once stored by providing such an opening, there is an advantage that supply without screw pitch unevenness is possible. In addition, when deposited before the doctor, a region of the agent that does not move is formed. With such a configuration, the generation of the developer that has been subjected to stress for a long time can be suppressed as much as possible.

Further, according to the present invention, the developer supply amount is monitored by monitoring the deposition amount before or after the regulating member, and if the accumulation amount is large, a feedback mechanism that reduces the supply amount or a feed that suppresses fluctuations in the supply amount as much as possible. A forward mechanism is adopted. In this way, the amount of deposition is controlled, and excessive developer is suppressed as much as possible to suppress the generation of stressful developer, and when developing a latent image, development is performed with substantially the same thin film thickness. It is possible to provide ideal conditions for development in digitization.
In particular, there is a method of adjusting the supply amount of the developer by monitoring an increase (decrease) in the deposition amount of the developer, monitoring a transmission amount by a light sensor, monitoring an image, a concentration of the agent, or the like. Among these, it is desirable to adopt a method of sensing pressure, for example, because it is possible to make an inexpensive and simple configuration. However, in an actual developer, since it is necessary to maintain the relationship between the supply amount and the passage amount, a feedback or feedforward mechanism for adjusting the agent supply amount is further employed.

(Embodiment 1)
A first embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a printer), which is an image forming apparatus, will be described below.
FIG. 1 is a schematic configuration diagram showing the configuration of the developing device. FIG. 2 is a schematic configuration diagram showing the configuration of the process cartridge.
First, the image forming apparatus (for example, a printer) includes a charging device 2 that is a charging unit that charges the photosensitive member 1 and a latent image that forms a latent image on the photosensitive member 1 around the drum-shaped photosensitive member 1 that is an image carrier. It has an exposure device that is an image forming unit, and a developing device 3 that is a developing unit that develops a latent image on the photoreceptor 1. Around the photosensitive member 1, a transfer device that is a transfer unit that transfers a toner image on the photosensitive member 1 to a transfer material, a charge eliminating device that removes the residual potential of the photosensitive member 1, and a transfer residual toner on the photosensitive member 1 are removed. It has a cleaning device which is a cleaning means. The image forming apparatus of the present invention has a developing device described below or a process cartridge having such a developing device.
As shown in FIG. 1, the surface of the photoreceptor 1 is uniformly charged to a predetermined positive or negative potential by the charging device 2 while being rotationally driven in the direction of arrow A in the figure at a predetermined peripheral speed. Next, light corresponding to the image is irradiated by an exposure apparatus such as slit exposure or laser beam scanning exposure to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 3 to be visualized. The toner image formed on the photoconductor 1 by the developing device 3 is transferred to a transfer material conveyed from the paper feeding unit between the photoconductor 1 and the transfer device in synchronization with the rotation of the photoconductor 1. Is transcribed by. The transfer material onto which the toner image has been transferred is separated from the surface of the photoreceptor 1 and sent to the fixing device, where the image is fixed by the action of heat and pressure, and printed out as a copy.
After the image transfer, the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning device, and after the residual potential is erased by the static eliminator, it is repeatedly used for image formation. Note that the configuration of the printer is not limited to this. For example, instead of a drum-shaped photoreceptor, a belt-shaped photoreceptor may be used. An intermediate transfer member may be used for transferring the toner image.

Here, as shown in FIG. 2, the photosensitive member 1, the charging device 2, and the developing device 3 are integrally coupled as a process cartridge 4 and configured to be detachable from the printer main body. Thereby, maintainability and exchangeability can be improved even for long-term use of the printer. The members incorporated in the process cartridge are not limited to the photosensitive member 1, the charging device 2, and the developing device 3. For example, a cleaning device may be further added.
As shown in FIG. 1, the developing device 3 is provided on the side of the photosensitive member 1, and a developing sleeve 5 as a developer carrying member is formed as an agitation storage portion in which an opening is formed toward the photosensitive member 1. A part of the developer container 6 is exposed from the opening.
The developing sleeve 5 is rotationally driven by a driving means (not shown), and includes therein a magnet roll 7 composed of a plurality of fixed magnets as a magnetic field generating means fixedly arranged. The magnet roll 7 has five magnetic poles S 1, N 2, S 2, S 3, and N 1 in the rotation direction of the developing sleeve 3 from the position of the developing position that is a region facing the photoreceptor 1. The magnetic pole arrangement in FIG. 1 is a configuration example, and the number and arrangement of the magnetic poles are not limited to this. Accordingly, the developing sleeve 5 carries a two-component developer (hereinafter referred to as “developer”) 10 including the toner 8 and the magnetic carrier 9 on the surface as a magnetic brush.

The developer 10 obtains a specified charge amount by mixing the toner 8 and the magnetic carrier 9 by a stirring member 11 made of a screw installed in the developer container 6.
The toner charge amount on the developing sleeve 5 is preferably in the range of −10 to −25 [μC / g]. The toner 8 contains a magnetic material and can also be used as a one-component magnetic toner. In the developing device 3 configured as described above, the developer 10 on the developing sleeve 5 is conveyed as the developing sleeve 5 rotates in the direction of arrow B, and the layer thickness is regulated by the developer regulating member 12 to be thinned. . The thinned developer 10 is conveyed to a developing position which is a position facing the photosensitive member 1 rotating in the direction of arrow A. A developing bias is applied to the developing sleeve 5 by a power source (not shown), and at this developing position, the toner 8 in the developer 10 is supplied to the electrostatic latent image formed on the surface of the photosensitive member 1 and electrostatically charged. The latent image is visualized and developed.

The developing gap GP, which is the gap between the photosensitive member 1 and the developing sleeve 5, can be set in the range of 0.8 mm to 0.4 mm, and the developing efficiency can be improved by reducing the value. In the present embodiment, specific development conditions are as follows. The diameter of the photoreceptor 1 is 50 mm, for example, and the linear velocity is 200 mm / sec. The developing sleeve has a diameter of 18 mm and a linear velocity of 300 mm / sec. The linear velocity of the developing sleeve 5 is mainly 200 to 300 mm / sec. The developing process is performed with the charging potential V0 of the photoreceptor 1 before exposure set to -350V, the potential VL after exposure set to -50V, and the developing bias voltage VB set to -250V, that is, the developing potential (VL-VB = 200V). At this time, | VD−VL |> | VL−VB |.
The developing device 5 according to the first embodiment has a developer amount (hereinafter, referred to as a developer amount) held by a magnetic pole N1 that is upstream of the developer regulating member 12 in the developer transport direction and is opposed to the developer regulating member 12. The amount of developer accumulated before the developer regulating member) is equal to or less than twice the amount of developer passing through the developer regulating member 12. The developer accumulation amount before the developer regulating member is the developer amount from the position facing the developer regulating member 12 on the developing sleeve 5 to the position where the normal magnetic density distribution value of the magnetic pole N1 becomes zero. . The developer amount is measured by once rotating the developing sleeve 5 and then taking out the developing sleeve 5 out of the developing device 3 while holding the developer regulating member 12 and collecting the developer 10 at the above location. do it.

Next, the first embodiment will be described. FIG. 5 shows the configuration of the first embodiment. FIG. 4 shows a conventional apparatus configuration shown for comparison.
As shown in FIG. 5, in the image forming apparatus according to the first exemplary embodiment, an adjusting unit that adjusts the sending amount (flow rate) of the developer is provided upstream of the agent regulating member 12.
For example, in FIG. 5, the developer supply unit 13 is installed on a path through which the developer 10 is supplied from the stirring member 11 to the developing roller 5. The developer supply unit 13 has an opening 13-1, and the agent is supplied onto the developing roller 5 through the opening 13-1. At this time, the size of the opening 13-1 can be changed to restrict the amount of developer held on the developing sleeve. In the first embodiment, the agent accumulation unit 13-2 can be provided so as to prevent an excessive stress from being applied to the developer. When passing through the agent accumulation portion 13-2 and the opening portion 13-1, the agent and the carrier efficiently come into contact with each other to increase the charging due to friction with the agent, or to increase the stirring efficiency. Development in front of the regulating member by roughening the inner surfaces of the stacking portion 13-2 and the opening portion 13-1 to increase frictional charging or increasing the toner charging efficiency by friction with the roughened inner surface. The charging of the agent can be efficiently generated, or the stirring effect by the stirring member can be increased by roughening the inner surface of the agent stacking portion 13-2. The developer supply unit 13 having at least one of the opening 13-1 and the agent accumulation unit 13-2 is formed of a nonmagnetic member, and the roughening is performed by a known roughening treatment method, for example, It can be performed using a method such as a sandblast treatment, a flame method, a plasma treatment, or a physical treatment such as electrical decoration.
In the first embodiment, the developer is temporarily accumulated in the developer supply mechanism 13. However, since it is held in a lower magnetic field than when it is deposited on the developer regulating member, the stress received is reduced. Further, in this configuration, the accumulated developer is supplied onto the sleeve within a certain time, so that excessive stress is not applied.

Hereinafter, the developing device according to the first exemplary embodiment will be specifically described based on examples.
In this embodiment, the opening area of the developer supply mechanism 13 is changed, and the developer accumulation amount before the developer regulating member is changed as shown in FIG. Prepared. Here, the doctor gap is set so that the amount of developer passing through the developer regulating member 12 is 0.5 mg / cm ² . Then, after driving only the developing device for 20 minutes with the linear velocity of the developing sleeve 5 being 200 mm / sec, the developer in the developer container 6 is sampled, and the buried state of the external additive of the toner 8 is observed with an electron microscope. Observed at. The result is shown in FIG. From the results of FIG. 3, it can be seen that in Examples 1 and 2 in which the amount of developer deposited before the developer regulating member was doubled or less, the buried state of the external additive of the toner was improved.

(Embodiment 2)
Next, Embodiment 2 in which the agent supply unit is changed in the developing device 3 will be described with reference to FIG.
In the invention of the developing device or the like according to the second embodiment, the agent regulating member 12 is disposed on the upper side of the developing sleeve, and the agent supply unit 13 is provided in front of the agent regulating member 12 and on the developing sleeve. For example, the developer passes through the supply port 14 described in the first embodiment and is supplied onto the developing sleeve. In the developing device shown in FIG. 6, the developer is supplied through or without a magnetic pole such as a pumping pole, and this developer is held by a magnetic field by a magnet disposed in the developing sleeve 5 to rotate the sleeve. Is carried onto the photoreceptor 1 on which the latent image is carried. On the way, when the developer passes through the agent regulating member 12, the developer is moderately charged by friction between the toner and the carrier, and the developer regulating member 12 causes the variation of the agent to be stably and to have a constant layer thickness. Will be formed and carried to the development area.
With such a developing device, it is possible to provide a developing device capable of forming a high-quality image by using the agent at a low diameter with little deterioration of the agent.
The stirring unit 15 is installed outside (for example, outside the effective magnetic field range), and is sufficiently supplied to the member 13 that adjusts the supply amount after sufficiently stirring the carrier and the toner. In the second embodiment, the supply amount adjusting member 13 is adjusted by the opening 14 so that the developer is supplied downward as shown in FIG.
In this adjustment function, since the agent is maintained in a state where no magnetic field is applied, even if it is deposited, no strong stress is applied, so that the developer does not deteriorate. A predetermined amount of developer is supplied to the developing carrier through such an opening.
The degree of deterioration of the developer in this embodiment is further improved than that in the first embodiment. The stirrer 15 shown in FIG. 6 is performed using the stirrer shown in the first embodiment, and the magnetic force in the developing roller is increased so as to reduce the energy of the developer from the stirrer 15 to the agent supply unit 13 as much as possible. Utilizing and transporting to the agent supply unit 13 is also included in the aspect of the present embodiment.

(Embodiment 3)
In the present embodiment, a sensor 16 that detects pressure or the like is installed in the developer regulating member 12 or the like in the developing device described in the second embodiment, and the amount of developer is adjusted using information sensed by the sensor 16. It is characterized by doing.
The detail of the agent supply part 13 in this embodiment is shown in FIG. This will be described with reference to FIG.
In the third embodiment, the pressure sensor 16 is installed on the back side of the agent regulating member 12. The regulating member 12 does not have to be strong, and in the example of the present embodiment, Al is used with a thickness of 0.5 mm. Although not shown, both ends of the regulating member 12 are held by the developing device.
For example, as described above, an example of adjustment will be described with reference to the flowchart shown in FIG. 8 in the case where the pressure sensor 16 is installed as a sensor at, for example, the end of the developer regulating member 12 and is controlled by the feedback control method. To do.

When the image forming process is performed (start), the presence / absence of sensor output from the sensor is confirmed (step S1). In step S1, if there is an output and the sensor output is confirmed (Yes in step S1), it is determined whether or not the value obtained by the sensor is within a predetermined value (step S2), and within the predetermined value (step S2). If a ≧ x ≧ b) (Yes in step S2), the current state is maintained (no operation of the electric shutter: step S3), and the process returns to step S1. If it is not within the predetermined value in step S2 (No in step S2), after determining whether the electric shutter is opened or closed (step S4), an appropriate operation of the electric shutter is performed (step S5), and thereafter Return to S1. If the measured value x is less than a in step S2 or exceeds b, the electric shutter is opened or closed. At this time, for example, in the case of driving the electric shutter and driving the stepping motor, two or more threshold values are provided (these are a1, a2,... (Where a1>a2>...)). ), In the case of a1 (the threshold is also the maximum), the trigger of n1 shots is divided once or divided into two or more to be driven periodically to drive the electric shutter to move the electric shutter by a predetermined amount, In the case of a2, n2 triggers are periodically generated to move the electric shutter by a predetermined amount. As described above, since the electric shutter is moved stepwise to move the predetermined amount, the deterioration of the developer can be extremely suppressed. In the above description, the case where the electric shutter is opened is discussed. However, the same applies to the closing direction. However, in this case, the threshold is b1 <b2 <. , An (n is an integer) are interpreted as b1,..., Bn (n is an integer), respectively.
Further, before returning from step S3 or step S5 to step S1, it is determined whether or not the image forming process is continued (step S6). If the image forming process is finished, the process is finished and continued. In that case, it is possible to return to step S1. Further, instead of the above-described step S2, it is possible to adopt a method in which feedback control is performed by taking a difference from the previous value or the reference value, determining which threshold the difference is, adjusting the electric shutter.
In this way, it becomes possible to adjust the supply amount of the developer according to the accumulation amount before the agent regulating member. For example, the developer accumulation amount can be controlled over time. In addition, a stable developer supply amount can be maintained even during long-term use, resulting in high image quality.

In the above-described third embodiment, the pressure sensor is used as the sensor and the adjustment with the feedback mechanism is described as an example.
However, in the third embodiment, a sensor other than the pressure sensor may be used as the sensor. For example, an optical sensor or an acoustic sensor may be used.
For example, an optical sensor has a light emitting element and a light receiving element, and senses reflected light, or senses reflected sound by a transmitting element and a microphone, and is controlled and adjusted by a feedback mechanism similar to that described above. It can also be. Furthermore, by using these optical or acoustic sensors, the electric shutter at the supply port of the agent supply unit can be adjusted by feedforward control of the supply port 14 of the agent supply unit with respect to fluctuations after the developer regulating unit 12. In the example shown in FIG. 7 of the third embodiment, an example in which the electric shutter is adjusted in one direction is shown, but a method of adjusting from both directions can also be adopted. In the present invention, the amount of developer held on the developer carrying member is adjusted to be not more than twice the amount of developer after passing through the developer regulating member. In both the feedback control method and the feedforward control method, control is performed so as to protect this. In this case, the lower limit of the adjustment amount of the developer amount is included to be 0 in the limit, and may include 0 to 1 times (exactly 0 to less than 1 time). Tends to periodically change a certain value (for example, 1 + δ ± a (δ, a is a positive minute amount)).
In the present invention, the developing device described in the first to third embodiments is formed as a process cartridge. According to the cartridge having such a developing device, the developing device 5, the photoreceptor 1, the charging device 2, and the like. Can be attached to and detached from the printer body as an integral structure, and maintainability and exchangeability can be improved even in long-term use. Further, according to the printer according to the present embodiment, the deterioration of the developer 10 is reduced even during long-term use, and a stable high-quality image can be obtained.

FIG. 2 is a schematic configuration diagram illustrating a main part of a developing device according to the present invention. 1 is a schematic configuration diagram of a process cartridge according to the present invention. FIG. 4 is an explanatory diagram showing a relationship between a developer amount regulation and a toner external additive buried state of the developing device according to the present invention. Sectional drawing which shows the structure of the conventional image development apparatus. FIG. 3 is a cross-sectional view illustrating a configuration of a developing device according to the present invention. FIG. 3 is a cross-sectional view illustrating a configuration of a toner supply amount control unit of the developing device of the present invention. FIG. 4 is a cross-sectional view illustrating a configuration of a toner supply amount control unit using a pressure sensor of the developing device of the present invention. 8 is a flowchart for controlling a toner supply amount using a developing device as shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor, 2 Charging apparatus, 3 Developing apparatus, 4 Process cartridge, 5 Developing sleeve, 6 Developer container, 7 Magnetic roll, 8 Toner, 9 Carrier, 10 Developer, 11 Stirring member, 12 Developer control member, DESCRIPTION OF SYMBOLS 13 Developer supply part, 14 supply port, 15 Stirring part, 16 Pressure sensor (sensor), 17 Developer supply part, 18 Supply port

Claims (7)

Development provided with a fixed magnetism generating means for generating a plurality of magnetic fields, a developer carrier comprising a sleeve that circulates around the fixed magnetism generator, and a developer regulating member that regulates the developer layer thickness on the developer carrier. Device,
A developer supply amount adjusting unit is provided in a path for supplying the developer onto the developer carrier, and the supply amount adjusting unit is a developer held on the developer carrier member before the developer adjustment. A developing device comprising adjusting means for adjusting the amount of the developer to be not more than twice the amount of the developer after passing through the developer regulating member.   The supply amount adjusting means is provided on the developer carrier from a supply port for controlling a conveyance amount of a mixing and stirring unit that stirs a developer component containing at least one selected from toner, carrier, and circulating developer. The developing device according to claim 1, wherein the developing device is supplied.   The developing device according to claim 1, wherein the developer supplied before the developer regulating member is at least partially charged before reaching the developer regulating member.   The developing device according to claim 2, wherein the supply amount adjusting unit adjusts by changing an opening area of the supply port.   5. The supply amount adjusting unit according to claim 1, wherein the supply amount adjusting means adjusts the supply amount of the developer according to an output signal of a difference before and after passing through the developer regulating member by a sensor. The developing device described.   A process cartridge in which at least one selected from a latent image carrier, a charging unit, and a cleaning unit and the developing unit are integrated and detachable from the image forming apparatus main body, and the developing unit includes: A process cartridge comprising the developing device according to claim 1.   An image forming apparatus comprising the developing device according to claim 1 or the process cartridge according to claim 6.

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