JP4822901B2 - Developing device, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to a developing device used for image formation by an electrostatic copying process such as a copying machine, a facsimile machine, and a printer, and also relates to an image forming device and a process cartridge using the developing device.

In recent years, office automation and colorization have further progressed in offices, and in addition to copying originals consisting only of conventional characters, originals including graphs created with a personal computer are output by a printer and used as presentation materials. Opportunities to copy sheets are increasing. Printer output images are mostly solid images, line images, and halftone images. Accordingly, market demands for image quality are changing, and demands for high reliability and the like are further increasing.
Developers used in electrophotographic systems such as electrophotography, electrostatic recording, and electrostatic printing are, for example, an image carrier (typically a photoreceptor) on which an electrostatic latent image is formed in the developing process. Then, the toner is transferred from the photosensitive member to a transfer medium such as transfer paper in the transfer process, and then fixed on the paper surface in the fixing process. At that time, as a developer for developing the electrostatic latent image formed on the image carrier, a two-component developer composed of a carrier and a toner, and a one-component system composed of only a toner without requiring a carrier. Developers (magnetic toner, non-magnetic toner) are known. In the two-component developer, the developer deteriorates due to the toner particles adhering to the carrier surface, and the toner concentration in the developer decreases because only the toner is consumed. Must be maintained at a constant rate, and therefore, there is a drawback that the developing device is increased in size. On the other hand, the one-component developer has the advantage that the apparatus can be downsized, and the development system is mainstream because it is easy to use in any environment (low temperature, low humidity, high temperature, high humidity). It is becoming.

  By the way, the one-component developer is classified into a magnetic one-component developer using a magnetic toner and a non-magnetic one-component developer using a non-magnetic toner. A magnetic one-component developing method using a magnetic one-component developer uses a developing sleeve provided with a magnetic field generating means such as a magnet inside to hold magnetic toner containing a magnetic material such as magnetite, and a layer thickness regulating member In many cases, it has been put into practical use in small printers. In contrast, in the non-magnetic one-component development method using a non-magnetic one-component agent, since the toner does not have a magnetic force, the toner supply roller or the like is pressed against the developing sleeve to supply the toner onto the developing sleeve, and electrostatic Since it does not contain a colored magnetic material, it has the advantage that it can be colorized and does not use a magnet for the developing sleeve. In recent years, it has been put to practical use in small full-color printers and the like.

However, in the one-component development system, there are still many problems to be improved. In the two-component development system, a carrier is used as a means for charging and transporting toner, and the toner and the carrier are sufficiently stirred and mixed in the developing device and then transported to the developing sleeve for development. However, it is possible to maintain stable charging and conveyance, and it is easy to cope with a high-speed developing device. Compared to this, the one-component development method does not have a stable charging / conveying means such as a carrier, and therefore, charging and conveyance defects are likely to occur due to long-term use and high speed.
In particular, in the non-magnetic one-component developing method, after toner is conveyed onto the developing sleeve, the toner is thinned by the layer thickness regulating member and developed, but the toner and the friction charging member such as the developing sleeve or the layer thickness regulating member are developed. Contact / friction charging time is very short, and therefore, low-charge and reverse-charge toner tends to increase more than in the two-component development system using a carrier. In addition, means for transporting the toner by at least one toner transport member and developing the electrostatic latent image formed on the image carrier by the transported toner is employed. The toner layer thickness must be as thin as possible. For this reason, in order to receive a pressing force by the layer thickness regulating member, there is a problem that the external additive added to the toner surface is embedded in the toner and the chargeability and fluidity of the toner are greatly reduced. .

To solve this problem, for example, Patent Document 1, a magnet Hollow as makeup roller replenishing port vicinity of the toner over replenishing tank and hopper - and La, in that and a scraper as bristle cutting means And a replenishing roller driving means capable of rotating the replenishing roller forward and backward, the replenishing roller driving means comprising a rotation angle A in the forward rotation direction of the replenishing roller within a predetermined time, An image forming apparatus that drives the supply roller so that the relationship with the rotation angle B in the reverse rotation direction satisfies A <B is disclosed. As a result, it is possible to prevent the fluidity of the toner in the hopper from deteriorating, the amount of toner supplied to the developing roller can be kept constant, and the image device can be made compact and free from blurring.
In Patent Document 2, the developing sleeve is provided with a conductive resin layer having a charging polarity of the same polarity as that of the developer on the surface, and the conductive resin layer includes at least a binder resin, a conductive fine powder, And a charge control agent, and a developing device in which the rotation center X of the stirring member is positioned below the horizontal plane H that crosses the rotation center of the developing sleeve is disclosed.

Japanese Patent Laid-Open No. 08-122559 JP 2005-062215 A

However, the technique disclosed above has a problem that it is difficult to stabilize the chargeability and fluidity of the toner of the non-magnetic one-component developer in the developing device over a long period of time.
Accordingly, the present invention has been made in view of the above-described problems, and a problem thereof is a developing device using a non-magnetic one-component developer, which reduces the chargeability and fluidity of the non-magnetic one-component developer. It is an object of the present invention to provide a developing device to be suppressed and an image forming apparatus using the same.

The features of the present invention, which is a means for solving the above problems, are listed below.
1. In the developing device according to the present invention, a developing unit that develops a latent image on an image carrier with toner and a toner cartridge that replenishes toner to the developing unit are arranged in parallel, and the developing unit is detachable. Has a first transport paddle for stirring the toner, the toner cartridge has a second transport paddle for stirring the toner, and a rib is provided on the bottom of the inner wall surface of the toner cartridge. a communication port for passing the toner by communicating with the toner cartridge, and a control valve for controlling the amount of toner passing through the continuous opening provided corresponding to the continuous opening, wherein the first transport paddle A plurality of paddle films, and the control valve contacts the paddle film of the first transport paddle to open the communication port; By swinging from a fixed position to an operating position to be closed and returning from the operating position to the fixed position, a first space portion that opens to the communication port is formed on the downstream side in the moving direction. There, the second transportation paddle has at least one elastic film, the elastic film makes contact before Symbol rib by rotation, the toner is dammed between the and the elastic film ribs, then the elastic film When the roller further rotates, the rib prevents the toner from being conveyed and the elastic film lifts the front toner in the rotation direction, thereby forming a second space portion on the downstream side in the moving direction. After the two space portions are formed, the control valve returns to a fixed position and the first space portion is formed by releasing the contact of the first transport paddle with the paddle film. The toner in the vicinity of the communication port lifted by the elastic film is supplied from the toner cartridge side to the developing unit through the communication port, and the toner in the vicinity of the communication port is supplied to the developing unit, The second space portion opens toward the communication port, and then the control valve comes into contact with the paddle film of the first transport paddle, and the control valve causes the toner in the developing unit to pass through the communication port. It is characterized by being discharged into two spaces .
2. The developing device of the present invention is further characterized in that the shape of the communication port is a rhombus.
3. The developing device of the present invention is further characterized in that the adjacent control valves are driven alternately.
4). The developing device of the present invention is further characterized in that each of the control valves includes a rigid support portion and an elastic operation portion.
5. The developing device of the present invention is further characterized in that the width of the control valve is 0 mm to 20 mm larger than the width of the communication port.
6). The developing device of the present invention is further characterized in that the interval between the control valves is 2 mm to 20 mm.
7). The developing device of the present invention is further characterized in that the length of the control valve is 10 mm to 25 mm.
8). The developing device of the present invention is further characterized in that a valve angle at a fixed position of the control valve is 20 ° to 45 °, and a valve angle at an operating position is 0 ° to 15 °.

9. An image forming apparatus of the present invention includes an image carrier that carries a latent image, a charging device that uniformly charges the surface of the image carrier, an exposure device that writes an electrostatic latent image on the surface of the charged image carrier, A developing device that visualizes the electrostatic latent image formed on the surface of the image carrier, a transfer device that transfers the visible image on the surface of the image carrier directly or via an intermediate transfer member, and an image carrier using a cleaning device for cleaning the toner on the body, in an image forming apparatus and a fixing device for fixing with heat and or pressure to the visible image on a recording member, a developing device according to any one of 1 to 8 It is characterized by that.
10. According to another aspect of the present invention, there is provided an image forming apparatus including a process cartridge that integrally supports an image carrier and a developing device and is detachable.

11. The process cartridge according to the present invention uses at least the developing device according to any one of 1 to 8 above in a process cartridge that integrally supports at least the image carrier and the developing device and is detachable from the image forming apparatus main body. It is characterized by.

  By the means for solving the above, in the developing device and the image forming apparatus of the present invention, the chargeability of the toner is maintained, so that a stable charge amount can be obtained over a long period of time, so that a high-quality image can be obtained. . In addition, since the decrease in toner fluidity can be suppressed, the toner can be stably supplied to the developing sleeve, whereby an image having a high density can be stably obtained over a long period of time.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

FIG. 1 is a schematic view showing the configuration of the developing device of the present invention.
The developing device 30 includes a developing unit 31 that develops the latent image of the photoconductor 11 as an image carrier with toner as a developer, and a toner cartridge 32 that replenishes the developing unit 31 with toner.
The developing unit 31 is opposed to the photosensitive member 11 and supplies a toner onto the developing sleeve 31a, which is a developer carrying member that conveys the toner to a developing region formed between the developing unit 31 and the developing sleeve 31a. Supply roller 31b, a regulation roller 31c that is a layer thickness regulation member that regulates the amount of toner on the developing sleeve 31a, and a first conveyance paddle 31d that conveys toner.
The toner cartridge 32 includes first and second storage chambers 321 and 322 that store toner, second and third transport paddles 32a and 32b that transport the toner to the developing unit 31, and a second transport paddle 32a. A protruding rib 35 is provided at the bottom of the toner cartridge 32 where the toner cartridge rotates.
Here, a one-component developer is used as the developer. In contrast to replacing the developer as will be described later, it is very difficult to separate the toner from the carrier once mixed with the two-component developer. In the case of a one-component developer, the developer in the toner cartridge 32 and the developing unit 31 is basically the same and can be replaced, and can be applied to the developing device 30 of the present invention. In particular, it is preferable to use a non-magnetic one-component developer even for a one-component developer. In the non-magnetic one-component developer, the external additive on the toner surface has a great influence on the chargeability and fluidity of the toner. In a magnetic one-component developer, developability can be controlled by the strength of magnetization depending on the amount of magnetic material. In the non-magnetic one-component developer, the developability is greatly influenced by the charge amount and fluidity due to the external additive. Therefore, when used in the developing device 30 of the present invention, a stable toner surface state can be obtained.

In the developing device 30, the developing unit 31 and the toner cartridge 32 are arranged in parallel in the horizontal direction. Further, the toner cartridge 32 and the developing unit 31 are provided with a communication port 33 through which the toner passes between the toner cartridge 32 and the developing unit 31. Further, a control valve 34 is provided at the communication port 33 on the developing unit 31 side.
The developing device 30 of the present invention allows the toner to pass through the communication port 33. As a result, the toner consumed in the developing unit 31 is supplied from the toner cartridge 32 to the developing unit 31, and the toner deteriorated in the developing unit 31 is discharged from the developing unit 31 to the toner cartridge 32 through the communication port 33. Put out. The toner cartridge 32 can be replaced independently of the developing unit 31 independently.
The toner is subjected to a pressing force by the toner supply roller 31b and the regulating roller 31c in the developing unit 31. By receiving this pressing force, irregularities on the surface of the toner are chipped and the surface becomes smooth, and the adhesion to the photoconductor increases, making cleaning difficult. Therefore, when the environment becomes low humidity, cleaning failure may occur. In addition, although transferability is improved, fogging appears on a white background portion that has not been visually observed even if it has been transferred conventionally. Further, when the toner is pressed, the external additive present on the toner surface is buried inside the toner. This will be described in detail later with regard to the external additive, but the external additive is harder than the toner, and is therefore buried in the toner. As the external additive present on the toner surface decreases, the chargeability of the toner changes. In particular, since silica used as an external additive has a large specific surface area, the charge amount is high, and the charge amount of the toner varies greatly depending on the amount of the external additive on the toner surface due to burying. Another effect is that the fluidity of the toner is reduced by burying the external additive. This fluidity indicates the adhesion force of the toner. If the fluidity is high, the adhesion force between the toner and, for example, the photoreceptor is reduced. Similarly, the developability is improved by reducing the adhesion between the developing sleeve 31a and the toner. On the contrary, when the amount of the external additive existing on the toner surface is reduced due to the embedding, that is, the fluidity of the toner is lowered and the developability is lowered.

Therefore, in the developing device 30 of the present invention, the toner in the developing unit 31 is temporarily supplied to the toner cartridge 32 through the communication port 33 for supplying the toner consumed in the developing unit 31 from the toner cartridge 32 to the developing unit 31. The toner cartridge 32 is discharged and mixed with non-deteriorated toner in the toner cartridge 32 to reduce the existence ratio of the deteriorated toner amount, and then is supplied to the developing unit 31 through the communication port 33 and replenished. .
FIG. 2 is a schematic view showing the structure of the control valve 34 disposed in the developing unit 31 in the developing device of the present invention. The control valve 34 is provided corresponding to the communication port 33 of the developing unit 31, and the film 34 b is attached to the support portion 34 a and is disposed in the housing. As shown in FIG. 2, the control valve 34 has a rectangular shape corresponding to each communication port 33, and the portions without the communication port 33 are alternately provided without the control valve 34. The support portion 34a is made of a metal having rigidity and uses SUS, Cu, or Al. Film 34b is a resin film arm with resilient, polypropylene, polyethylene, polyester resin, fluorine resin is used.
The first transport paddle 31d of the developing unit 31 includes a paddle film. This film may be a single film or a plurality of films. The first transport paddle 31d rotates and supplies the toner supplied from the toner cartridge 32 side to the developing sleeve 31a. The film may be plate-shaped. In addition, for the comb-like rectangular control valve 34 provided corresponding to the communication port 33, only the portion corresponding to the control valve 34 may be rectangular. Moreover, when providing two or more sheets, you may use combining these.

FIG. 3 is a diagram for schematically explaining a state in which toner is supplied to the developing unit 31 from the toner cartridge 32 side. The first transport paddle 31d rotates to hit the control valve 34, and the control valve 34 is pressed. Thereafter, the first transport paddle 31d passes, and the elastic control valve 34 is quickly bounced back, and at the same time, the toner pushed in from the toner cartridge 32 side passes through the communication port 33 and the developing unit 31. The toner is supplied by being attracted to the side.
FIG. 4 is a diagram for schematically explaining a state in which the toner on the toner cartridge 32 side is supplied. The toner cartridge 32 is transported to the first storage chamber 321 by the third transport paddle of the second storage chamber 322, and further transported to the developing unit 31 side by the second transport paddle. The second transport paddle includes a single paddle film, and transports the toner toward the developing unit 31 by rotating the film. Further, by providing the rib 35 in the first storage chamber 321, as shown in FIG. 5, when the previous paddle film hits the rib 35, the toner is blocked by the rib 35, and the rib 35 and paddle A space without toner is formed between the film for use. This space is gradually filled by the intrusion of toner with good fluidity, but a space is formed inside the toner for a certain period of time. Further, when the paddle film rotates, the toner also enters the space from above, so that there is no space inside the toner.
As the paddle film rotates in this state, the control valve 34 of the developing unit 31 is pressed against the paddle film of the first transport paddle 31d when the toner is pushed into the developing unit 31 side. The toner is moved and supplied from the toner cartridge 32 side to the developing unit 31 side through the communication port 33 by overlapping with the time when the control valve 34 is open (when it is in a fixed position).
Next, the toner in the developing unit 31 enters the opened control valve 34. After that, the paddle film of the first transport paddle 31d rotates and the toner that pushes the control valve 34 is pushed from the developing unit 31 side to the toner cartridge 32 side and the paddle for the second transport paddle in the first storage chamber 321. A space is formed inside the toner by the film, and the toner is moved and discharged from the developing unit 31 side to the toner cartridge 32 side through the communication port 33 by overlapping when the space reaches the communication port 33.

The movement of the first, second and third transport paddles and the movement of the toner between the developing unit 31 and the toner cartridge 32 in the developing device 30 at this time will be described in more detail.
FIG. 5 is a diagram schematically illustrating toner movement between the developing unit 31 and the toner cartridge 32. Here, the developing sleeve 31a and the like in the developing unit 31 are omitted.
In the developing device 30, as shown in FIG. 5A, the control valve 34 in the developing unit 31 has a predetermined angle θ with respect to the wall surface provided with the communication port. The first transport paddle 31d rotates a plurality of paddle films. The second and third transport paddles in the toner cartridge 32 rotate a single paddle film. As shown in FIG. 5 (2), in the developing unit 31, a plurality of paddle films push the control valve 34 in the first transport paddle 31 d, and at this time, the first transport paddle 31 d is between the control valve 34 and the communication port 33. Since the toner cartridge 32 side is also filled with toner, the toner cannot move through the communication port 33 and returns from the control valve 34 in the developing unit 31 into the developing unit 31 in the lateral direction. Next, as shown in FIG. 5 (3), in the first transport paddle 31 d, a plurality of paddle films push the control valve 34 further, and there is almost no gap between the control valve 34 and the communication port 33 ( (Operating position). Next, as shown in FIGS. 5 (4) and 5 (5), the first transport paddle 31d has a plurality of paddle films separated from the control valve 34, so that the control valve 34 is at its original angle (fixed position). At this time, a large gap is formed, and the toner is moved and supplied from the toner cartridge 32 side through the communication port 33 by forming a space.
Further, as shown in FIG. 5 (6), the paddle film of the first transport paddle 31d pushes the control valve 34 again by having a plurality of sheets. At this time, the paddle film of the second transport paddle is in contact with the rib 35 in the second storage chamber 322 in the toner cartridge 32. When further rotated, as shown in FIG. 5 (7), the paddle film of the first transport paddle 31 d further pushes the control valve 34, and a state without a gap is formed between the control valve 34 and the communication port 33. At this time, when the paddle film of the second transport paddle is rotated first from the rib 35, the rib 35 becomes an obstacle and the toner is not transported, so that a space is formed inside the toner. Further, as shown in FIGS. 5 (8) and 5 (9), the first transport paddle 31d is moved back to the original angle when the plurality of paddle films are separated from the control valve 34. In addition, by forming a space with a large gap, the toner lifted by the paddle film of the second transport paddle is further moved and supplied from the toner cartridge 32 side through the communication port 33.
However, next, as shown in FIG. 5 (10), the paddle film of the first transport paddle 31d pushes the control valve 34 again by having a plurality of sheets. Until now, there has been toner in the vicinity of the communication port 33 on the toner cartridge 32 side. However, when there is a space formed inside the toner, the developing unit 31 extends laterally from the control valve 34 in the developing unit 31. Instead of returning to the inside, the toner moves from the developing unit 31 side to the toner cartridge 32 side through the communication port 33 and is discharged. As shown in FIGS. 5 (11) and 5 (12), the paddle film of the first transport paddle 31 d pushes the control valve 34 again to further move from the developing unit 31 side to the toner cartridge 32 side. It is moved and discharged.
Further, by making the rotation speed of the first transport paddle 31d faster than that of the second transport paddle, as shown in FIGS. 5 (13) to 5 (16), the first transport paddle 31d moves from the developing unit 31 side to the toner cartridge 32 side. It can be discharged.
By repeating this, the toner can be moved through the communication port 33 between the developing unit 31 and the toner cartridge 32.

Here, by controlling the rotational speeds of the first transport paddle 31d in the developing unit 31 and the second transport paddle in the toner cartridge 32, the amount of supply / discharge due to the movement of the toner can be adjusted. In particular, by making the rotation speed of the first transport paddle 31d in the developing unit 31 faster than the second transport paddle in the toner cartridge 32, the number of times the space formed inside the toner contacts the communication port 33 can be reduced. By increasing the number of times the first transport paddle 31d pushes the control valve 34, the number of times of supplying the toner through the communication port 33 can be increased.
Further, the amount of supply / discharge due to the movement of the toner can be adjusted by the number of communication ports 33, and therefore one or more communication ports 33 can be provided. The number of the communication ports 33 is appropriately determined according to the image forming speed of the image forming apparatus main body.
Moreover, the control valve 34 provided corresponding to the communication port 33 is provided in the shape of a comb, and the adjacent control valves 34 can be operated alternately. This is because the paddle film of the first transport paddle 31d is provided in every other comb tooth shape corresponding to the comb tooth shaped control valve 34, and all the control valves 34 are composed of two paddle films. The control valves 34 can be operated alternately corresponding to the above. By alternately operating, the toner can be discharged evenly without forming a dead space of toner in the developing unit 31.

FIG. 6 is a view showing a first transport paddle according to the present invention. It is a perspective view of the 1st conveyance paddle used suitably for the present invention.
The first conveyance paddle 31d has films 311 and 312 attached to a shaft having a quadrangular cross section, and two of the films extend in opposite directions on opposite surfaces. The opposing film 311 has a concavo-convex shape (comb shape), and is a shape that shifts the two convex portions. In this way, adjacent control valves 34 can be driven alternately. The uneven portion corresponds to the position of the communication port 33, and the control valve 34 provided at the communication port 33 has a length that allows the convex portion of the film to be pushed in, and the concave portion does not contact the control valve 34.
Further, the base portion of the convex portion of the film is formed in a “C” shape so as to be wider than the leading end portion, and when the first transport paddle 31d rotates, the toner is also fed in the longitudinal direction by the convex portion of the film. A moving force is generated to cause longitudinal stirring in the developing unit 31.
Further, by the rotation of the first transport paddle 31d, the convex portion of the film pushes the control valve 34 and returns the toner under the control valve 34 to the toner cartridge 32 side. This movement will be described later.
Since the first transport paddle 31d is set to rotate faster than the second transport paddle 32a, the control valve 34 is operated several times by the first transport paddle 31d within the time when the cartridge has space. The toner can be returned to the toner cartridge 32 efficiently.
When the convex portion of the film passes through the control valve 34, the control valve 34 is released from the pressing force and returns to its original state by elasticity, and the toner on the control valve 34 is sent to the developing unit 31 side, and the toner is placed below the control valve 34. A space for drawing the toner in the cartridge 32 is formed.
By shifting the convex portions of the two films 311 of the first transport paddle 31d, the control valves 34 are alternately pushed and released, that is, the adjacent control valves 34 are driven alternately to develop the inside of the developing unit 31. The movement of the toner is improved, and the circulation property with the toner in the toner cartridge 32 can be improved.

Here, by adopting the paddle having the two comb-like films as described above, the circulation property of the toner and the stirring property in the longitudinal direction are improved. There is a tendency for the toner to increase, and the toner surface in the developing unit 31 undulates vertically, creating peaks and valleys. If the communication port 33 is clogged, the supply of toner from the toner cartridge 32 is hindered, so that the amount of toner supplied to the entire developing unit 31 is reduced. Further, since toner flows from the toner cartridge 32 in the vicinity of the bottom of the toner peak, a phenomenon that uniformity of toner agitation is not ensured is observed. In order to improve this point, as a result of the examination, the interdigital film 311 and the interdigital film 311 are at an angle of 90 degrees between the two interdigital films and are shorter than the convex parts of the interdigital film. By adding a non-existing film, that is, a rectangular film 312 to the first conveyance paddle 31d, the toner pile at the communication port 33 was broken, and the toner surface in the developing unit 31 could be made almost horizontal.
As described above, by arranging the rectangular film 312 between the two comb-shaped films 311 in the first transport paddle, the amount of toner supplied from the toner cartridge 312 and the toner to the toner cartridge 32 are set. It is possible to achieve a sufficient circulatory action with a stable return amount. In addition, since a local toner flow is not formed, uniform agitation can be maintained in the developing unit 31.
FIG. 7 is a diagram showing the shape of the communication port according to the present invention. As shown in FIG. 7, the communication port has a rhombus shape. In this embodiment, the shape is a rhombus, but may be a rectangular shape or an ellipse. In the case of a rhombus shape, the width per communication port can be taken more effectively than a rectangular shape, and the toner can be more diffused in the longitudinal direction. In addition, the number of control valves can be reduced.

The width of the control valve 34 is 0 mm to 20 mm larger than the width of the communication port 33. If the control valve 34 is smaller than the communication port 33, the communication port 33 to which toner is supplied is blocked with toner on the developing unit 31 side, so that it is difficult to supply toner. Further, in discharging the toner, toner enters between the control valve 34 and the communication port 33, and a large amount of toner is discharged from the developing unit 31 side to the toner cartridge 32 side through the communication port 33 by discharging the inserted toner. However, since the width of the control valve 34 is reduced, a large amount of toner is discharged and the toner in the developing unit 31 is reduced.
On the other hand, toner is discharged from the side of the control valve 34 between the control valve 34 and the communication port 33 through the communication port 33 when the first transport paddle 31d is pushed. For this reason, when the width of the control valve 34 is larger than the communication port 33, the amount of toner that wraps around the communication port 33 is reduced, the amount of discharged toner is reduced, and toner replacement is reduced. The toner supplied from the communication port 33 moves downward from the communication port 33 and is mixed with the toner under the control valve 34. Therefore, when the width of the control valve 34 is increased, the number of supplied toners is reduced, and the homogeneity due to the mixing of the toner is lowered.
For these reasons, the width of the control valve 34 is at least the width of the communication port 33 and less than 20 mm. By setting this width, it is possible to easily control the supply / discharge of the toner, and to improve the homogeneity due to the mixing of the toner after the supply.

Further, the interval between the control valves 34 is set to 2 mm to 20 mm. When the distance between the control valves 34 is less than 2 mm, the amount of toner entering between the control valve 34 and the communication port 33 is small, and the amount of toner that can be discharged is small. Further, if it exceeds 20 mm, the number of communication ports 33 that can be provided decreases, and the amount of toner supplied and discharged decreases.
Moreover, the length of the control valve 34 shall be 10 mm-25 mm. The size of the space formed between the control valve 34 and the communication port 33 is determined by the length of the control valve 34. Therefore, if the control valve 34 is less than 10 mm, the amount of discharged toner is reduced, and toner replacement is insufficient. If it exceeds 25 mm, the amount to be discharged increases and the amount of toner in the developing hopper decreases.
Further, the valve angle at the fixed position of the control valve 34 is set to 20 ° to 45 °, and the valve angle at the operating position is set to 0 ° to 15 °. Since the control valve is elastic and bends, the valve angle here is defined as an angle formed by a straight line connecting a portion where the control valve is in contact with the wall surface and the tip of the control valve and the wall surface. The size of the space formed between the control valve 34 and the communication port 33 is determined by the angle of the control valve 34. Therefore, if the angle of the control valve 34 at the fixed position is less than 20 °, the amount of toner discharged becomes small, so that the toner replacement becomes insufficient. When it exceeds 45 °, the amount discharged becomes large and the amount of toner in the developing hopper becomes small.

FIG. 8 is a schematic diagram showing the configuration of the image forming apparatus of the present invention.
The image forming apparatus 1 includes a photosensitive unit 10, a writing optical unit 20, a developing unit 30, an intermediate transfer unit 40, a secondary transfer unit 50, a fixing unit 60, a duplex printing paper reversing unit 70, and the like. Then, black (hereinafter referred to as Bk), cyan (hereinafter referred to as C), magenta (hereinafter referred to as M), and yellow (hereinafter referred to as Y) color images are successively developed on the photoreceptor belt 11 of the photoreceptor unit 10. These are then superimposed to form the final four-color full color image. Around the photoreceptor belt 11, a photoreceptor cleaning device 12, a charging roller 13, a plurality of developing devices 30, an intermediate transfer belt 41 of an intermediate transfer unit 40, and the like are disposed. The photosensitive belt 11 is stretched between a driving roller 14, a primary transfer counter roller 15, and a stretching roller 16, and is rotated by a driving motor. The writing optical unit 20 converts the color image data into an optical signal, performs optical writing corresponding to each color image, and forms an electrostatic latent image on the photosensitive belt 11. The writing optical unit 20 includes a semiconductor laser 21 as a light source, a polygon mirror 22, three reflecting mirrors 23, and the like.
The developing device 30 includes, in order from the lower side of the main body of the image forming apparatus 1, a Bk developing device 30K containing black toner, a C developing device 30C containing cyan toner, an M developing device 30M containing magenta toner, and a yellow. A Y developing device 30Y containing toner is provided. Here, a contact / separation mechanism is further provided that moves each developing device in the horizontal direction in the drawing to perform contact / separation operation with respect to the photosensitive belt 11.

  The toner in the developing device 30 is charged to a predetermined polarity, and a developing bias is applied to the developing sleeve 31 a by a developing bias power source, and the developing sleeve 31 a is biased to a predetermined potential with respect to the photosensitive belt 11. The contact / separation mechanism moves the developing device 30 toward the photosensitive belt 11 by the driving force when an electromagnetic clutch (not shown) for transmitting driving from the motor to each developing device 30 is turned on. At the time of development, any one selected from the developing device 30 moves and contacts the photosensitive belt 11. On the other hand, when the electromagnetic clutch is turned off to cancel the drive transmission, the developing device that has been in contact with the photosensitive belt 11 moves away from the photosensitive belt 11.

In the standby state of the main body of the image forming apparatus 1, the developing devices 30K, C, M, and Y are also set at positions separated from the photosensitive belt 11, and when the image forming operation is started, the laser beam is based on the color image data. Is started, and electrostatic latent image formation is started (hereinafter, an electrostatic latent image based on Bk image data is referred to as a Bk electrostatic latent image; the same applies to C, M, and Y). Before the leading edge of the electrostatic latent image reaches the Bk developing position so that the leading edge of the Bk electrostatic latent image can be developed, the Bk developing sleeve 31a starts to rotate, and the Bk electrostatic latent image is transformed with Bk toner. develop. Thereafter, the developing operation of the Bk electrostatic latent image area is continued, but when the rear end portion of the Bk electrostatic latent image passes the Bk developing position, the K developing device 30K is separated from the photosensitive belt 11, The developing device of the corresponding color comes into contact with the photosensitive belt 11 in preparation for the development of the next color. This is completed at least before the leading edge of the electrostatic latent image based on the next image data reaches the developing position.
The intermediate transfer unit 40 includes an intermediate transfer belt 41, a belt cleaning device 42, a position detection sensor 43, and the like. The intermediate transfer belt 41 is stretched around a drive roller 44, a primary transfer roller 45, a secondary transfer counter roller 46, a cleaning counter roller 47, and a tension roller 48, and is driven and controlled by a drive motor (not shown). A plurality of position detection marks are provided in the non-image forming area at the end of the intermediate transfer belt 41. Any one of these position detection marks is detected by the mark sensor 43, and at this detection timing. Start image formation. Further, the belt cleaning device 42 includes a cleaning brush 42a, a contact / separation mechanism, and the like, while transferring the Bk image of the first color to the intermediate transfer belt 41 and the images of the second, third, and fourth colors. During the transfer to the intermediate transfer belt 41, the cleaning brush 42a is separated from the surface of the intermediate transfer belt 41 by the contact / separation mechanism.
Further, the secondary transfer unit 50 includes a contact / separation mechanism including a clutch or the like for contacting / separating the secondary transfer roller 51, the secondary transfer roller 51 with the intermediate transfer belt 41. The secondary transfer roller 51 swings about the rotation axis of the contact / separation mechanism in accordance with the timing when the transfer paper reaches the transfer position. The secondary transfer roller 51 and the secondary transfer counter roller 46 bring the transfer paper and the intermediate transfer belt 41 into contact with each other with a constant pressure. The secondary transfer roller 51 has a positional accuracy of parallelism with the secondary transfer counter roller 46 by a positioning member (not shown) provided in the intermediate transfer unit 40. Further, the contact pressure of the secondary transfer roller 51 with respect to the intermediate transfer belt 41 is made constant by a positioning roller (not shown) provided on the secondary transfer roller 51. At the same time as the secondary transfer roller 51 is brought into contact with the intermediate transfer belt 41, a transfer bias having a polarity opposite to that of the toner is applied to the secondary transfer roller 51, and the superimposed toner images on the intermediate transfer belt 41 are collectively transferred onto the transfer paper.

On the other hand, at the time when the image forming operation is started, the transfer paper is fed from either the transfer paper cassette 80 or the manual feed tray 83 and is waiting at the nip of the pair of registration rollers 82. Then, when the leading edge of the four-color superimposed toner image on the intermediate transfer belt 41 approaches the secondary transfer roller 51, the registration roller pair 82 is driven so that the leading edge of the transfer paper coincides with the leading edge of the toner image. The transfer paper and the toner image are aligned. Then, the transfer paper is superimposed on the toner image on the intermediate transfer belt 41 and passes through the secondary transfer position. At this time, the transfer paper is charged by the transfer bias by the secondary transfer roller 51, and most of the toner image is transferred onto the transfer paper. Then, the transfer paper onto which the four-color superimposed toner images are collectively transferred from the intermediate transfer belt 41 is conveyed to the fixing unit 60, and the toner image is melted at the nip portion between the fixing belt 61 and the pressure roller 62 controlled to a predetermined temperature. is fixed, is fed out of the apparatus main body, it is stacked face down in the discharge tray 8 4, obtaining a full-color copy.

Furthermore, when performing duplex printing, the transfer paper that has passed through the fixing unit 60 is sent to the duplex printing paper reversing unit 70 by the duplex switching claw 85. In the double-sided printing paper reversing unit 70, the transfer paper is first guided in the direction of arrow D by the reversal switching claw 71, and after the rear end of the transfer paper passes through the reversal switching claw 71, the reversing roller pair 72 stops and the transfer paper also Stop. Then, the reverse roller pair 72 starts reverse rotation after a certain blank time, and the transfer paper starts to switch back. At this time, the reverse switching claw 71 is switched, and the transfer paper is sent to the registration roller pair 82. The transfer sheet sent to the registration roller pair 82 stands by at the nip of the registration roller pair 82 with the front and back reversed. Then, the registration roller pair 82 is driven at a predetermined timing, the transfer paper is sent to the secondary transfer position, and the four-color superimposed toner image is collectively transferred from the intermediate transfer belt 41, and then the toner image is melted by the fixing unit 60. It is fixed and sent out of the main body.
On the other hand, the surface of the photoconductor belt 11 after the primary transfer can be cleaned by the photoconductor cleaning device 12 and uniformly discharged with a charge removal lamp or the like to facilitate cleaning. Further, the surface of the intermediate transfer belt 41 after the toner image is transferred onto the transfer paper is cleaned by pressing the cleaning brush 42a of the belt cleaning device 42 with a contact / separation mechanism. The toner cleaned from the intermediate transfer belt 41 is stored in a waste toner tank 49.

Here, the developing device will be further described in detail. The developing device 30 includes a developing sleeve 31a that rotates while carrying toner on the surface to develop an electrostatic latent image on the surface of the photoreceptor belt 11, and a toner first conveyance paddle 31d that rotates to pump up and stir the toner. And a toner cartridge 32 for containing toner. The reason why it is divided into two units in this way is that the developing unit 31 has durability that can withstand even if the toner cartridge 32 is replaced several times.
9A and 9B are schematic views showing the configuration of the communication port 33 in the developing device of the present invention. FIG. 9A shows the configuration on the developing unit 31 side, and FIG. 9B shows the configuration on the toner cartridge side. A slide shutter is provided outside the housing of the developing unit 31, and an elastic member is attached to the slide shutter. The communication port 33 of the developing unit 31 is opened and closed by opening and closing this slide shutter. Further, the toner cartridge 32 side is an elastic member having a portion corresponding to the communication port 33 provided in the housing, and is opened so that toner can be prevented from spilling from the communication port 33 or the toner can be replenished. A sliding shutter is provided, and a fixing seal for fixing these to the housing is provided.
By arranging the toner cartridge 32 in the developing device, the slide shutter on the developing unit 31 side is opened, and the slide shutter on the toner cartridge 32 side is opened to form a communication port 33 through which toner can pass.
There are a plurality of communication ports 33 on the developing unit 31 side, and a slide shutter with an elastic member attached is provided between the developing unit 31 and the toner cartridge 32. By moving the slide shutter, the communication port 33 provided in the housing of the developing unit 31 is opened and closed. When there is no toner cartridge 32 or when it is not attached to the image forming apparatus main body, the communication port 33 is closed with a slide shutter to prevent toner from spilling from the developing unit 31.
Further, when the developing unit 31 is not provided or the toner cartridge 32 is not attached to the main body of the image forming apparatus, the communication port 33 is closed in order to prevent the toner from spilling out from the toner cartridge 32. Provide a slide shutter. An elastic member, a slide shutter, and a fixed seal are provided for the toner cartridge 32. The elastic member is preferably a foamed material such as urethane resin or silicone resin.
As shown in FIG. 9, a window portion opened to the slide shutter is provided corresponding to the communication port 33 provided in the developing unit 31 and the toner cartridge 32. When the communication port 33 is closed, the communication port 33 is closed where there is no window portion of the slide shutter, and when the communication port 33 is opened, the slide shutter is moved so that the window portion and the communication port 33 are aligned with each other. To communicate.

In the image forming apparatus 1, the developing device 30 transports the toner to the developer supply roller 31b while stirring the toner with the first transport paddle 31d in the developing unit 31, and the supply roller 31b rubs against the developing sleeve 31a. At the same time, the toner is rubbed and frictionally charged to charge the toner. The charged toner is attracted to the developing sleeve 31a with a mirror image force and conveyed. Thereafter, the amount of toner conveyed to the development area is regulated by the regulation roller 31c. A thin toner layer formed on the developing sleeve 31a is developed on the photosensitive belt with a developing bias in the developing region.
At this time, the toner rubbed against the developing sleeve 31a by the supply roller 31b receives a large pressing force, and the irregularities on the surface of the toner are scraped to become spherical and increase the adhesion force of the toner. Further, the external additive on the surface of the toner is buried by this pressing force and the fluidity is lowered, and further, the charge amount cannot be adjusted by the external additive, so that the charge amount is changed. Under these influences, the developing property of the toner is lowered, and further, the transfer property and the cleaning property are lowered.
Thus, the amount of deteriorated toner increases in the developing hopper, and the toner in the developing unit 31 decreases because the toner is consumed by development. Therefore, the toner is supplied from the toner cartridge 32 to the developing unit 31 through the communication port 33. In the toner cartridge 32, a second transport paddle 32 a and a third transport paddle 32 b slidably contacted with the inner wall of the toner cartridge main body 32 are provided in the first storage chamber 321 and the second storage chamber 322, respectively. Alternatively, the third transport paddles 32 a and 32 b rotate to push the toner toward the developing unit 31, and the toner is supplied to the developing unit 31 from the communication port 33.

Further, the toner in the developing unit 31 is discharged to the toner cartridge 32 through the communication port 33, and the toner is mixed with the toner in the toner cartridge 32. A large amount of unused toner is stored in the toner cartridge 32 and is mixed with the deteriorated toner in the developing unit 31. As a result of this mixing, the external additive present in large amounts on the surface of the unused toner is redistributed to the deteriorated toner, whereby the charge amount and fluidity of the deteriorated toner become close to those of the original unused toner. This is because the toner discharged from the developing unit 31 to the first storage chamber 321 is further transported to the second storage chamber 322 by the second transport paddle, and then to the first storage chamber 321 by the third transport paddle. Returned. During this time, the external additive is redistributed.
The toner approaching the original unused state is supplied again from the first storage chamber 321 of the toner cartridge 32 to the developing unit 31. A high-quality image can be obtained over a long period of time by forming a thin layer on the developing sleeve 31a and developing the toner with the toner that has approached the original state and the unused toner.

  Next, the result of an Example and a comparative example is shown. In the comparative example, the control valve 34 and the rib 35 are omitted from the developing device 30K, and the films 311 and 312 of the first transport paddle 31d are replaced with a single paddle film as in the second transport paddle. With this configuration, in the case of the comparative example, the toner passing through the communication port 33 is almost one-way from the toner cartridge 32 to the developing unit 31 and passes through the communication port 33 as in the embodiment. The toner in the developing unit 31 is hardly discharged to the toner cartridge 32 side.

In order to compare toner chargeability between this example and the comparative example, the following experiment was performed. After setting the developing device 30K in the image forming apparatus 1 and outputting 10,000 sheets with an image area ratio of 3%, the toner in the developing unit 31 and the toner in the toner cartridge were respectively collected, and the charge amount of the toner was evaluated. . The evaluation of the toner charge amount was performed using an e-part analyzer manufactured by Hosokawa Micron Corporation shown in FIG.
Here, the espert analyzer can simultaneously determine the particle size and the charge amount by measuring the phase lag and the deflection amount of the charged particles that move by receiving the vibration of the sound wave and the action of the electric field by the laser Doppler method.

FIG. 11 shows the evaluation result of the toner charge amount of the example, and FIG. 12 shows the evaluation result of the toner charge amount of the comparative example.
In the case of the comparative example, a deviation occurs between the peak of the toner charge amount in the developing unit 31 and the peak of the toner charge amount in the toner cartridge. When toners having different charge amounts are mixed in this way, background stains are generated, and when the mixed amount is not uniform, vertical band-shaped density unevenness occurs.
On the other hand, in the example, it can be seen that the peak of the charge amount of the toner in the developing unit 31 and the peak of the charge amount of the toner in the toner cartridge substantially coincide. In the case of the example, no difference was observed in the charge amount, and even when 1000 sheets were output, a good image free from background stains and density unevenness could be obtained. This is because when the film pushes the control valve 34 by the rotation of the first transport paddle 31d, the toner under the control valve 34 returns to the toner cartridge 32 side, so that the toner in the toner cartridge 32 and the developing unit 31 This is because the toner is sufficiently replaced.
In this experiment, black toner was used for evaluation, but the toner in the toner cartridge 32 and the toner in the developing unit 31 are sufficiently contained even for other yellow, magenta, and cyan toners. I confirmed that it was replaced.

Next, in order to evaluate the toner charging stability over time, the following experiment was performed using the developing devices 30K of the example and the comparative example in the same manner as described above.
The image forming apparatus 1 is set with a developing device 30K in which the developing unit 31 and the toner cartridge 32 are sufficiently filled with toner (shipped as a product), and a toner end display is performed with an image area ratio of 2%. Image formation was performed until Thereafter, the toner cartridge 32 was replaced with a new one, and image formation was continued.
In order to evaluate the stability of toner charging over time in the example and the comparative example, (1) when the developing device 30K is set in the image forming apparatus, (2) when the toner end is displayed, and (3) new At each time when the toner cartridge is replaced (however, evaluation is performed when the developing device is operated for about 90 seconds after the replacement in order to see the toner mixing state), the toner on the developing sleeve 31a is collected and the toner is collected. The charge amount of was evaluated. The evaluation of the toner charge amount was performed with an e-part analyzer manufactured by Hosokawa Micron Corporation as described above.

FIG. 13 shows the results of the example, and FIG. 14 shows the results of the comparative example.
In both the examples and comparative examples, although the toner charge amount peak tends to shift toward the low reverse charge region over time, the increase rate of the low reverse charge toner is lower in the example than in the comparative example. It was confirmed that it was suppressed.
Here, regarding the toner charge amount, the high charge area is −2 (fc / μm: femtocoulomb / micrometer) or less, the low reverse charge area is −0.2 or more, and the middle area is the middle charge area. did. When the proportion of the toner in the low reverse charging area increases, background stains and density unevenness occur.

FIG. 15 shows the ratio of the low reversely charged toner at the time of replacement with a new toner cartridge. In the example, the ratio of the low reversely charged toner is reduced by about 35% compared to the comparative example, and the toner in the toner cartridge 32 and the toner in the developing unit 31 are sufficiently interchanged, which is good. The toner circulation was confirmed.
Further, FIG. 16 shows the toner collected at each time point (1) to (3) above divided for each charging area. Compared to the comparative example, in the case of the embodiment, the rate of change of the ratio of the toner in the high charging area and the low reverse charging area can be reduced, and the time from when the developing device 30K is set to when it is replaced with a new toner cartridge. During this time, the toner charge amount on the developing roller can be stabilized.

Subsequently, the above (1) to (3) are defined as one cycle, and the results when four cycles are performed are shown in FIG. In the second to fourth cycles, the toner charge amount on the developing roller is evaluated at an intermediate point between (1) and (2), and the result is added.
In all of the four cycles, it can be confirmed that the rate of change in the ratio of the toner in the high charge area and the low reverse charge area can be reduced in the case of the embodiment as compared with the comparative example. It became possible to stabilize the toner charge amount.

1 is a schematic diagram illustrating a configuration of a developing device of the present invention. It is the schematic which shows the structure of the control valve arrange | positioned at the image development unit in the image development apparatus of this invention. FIG. 6 is a diagram for schematically explaining a state in which toner is supplied from a toner cartridge side to a developing unit. FIG. 6 is a diagram for schematically illustrating a state in which toner on a toner cartridge side is supplied. FIG. 5 is a diagram schematically illustrating toner movement between a developing unit and a toner cartridge. FIG. 5 is a diagram schematically illustrating toner movement between a developing unit and a toner cartridge. FIG. 5 is a diagram schematically illustrating toner movement between a developing unit and a toner cartridge. It is a figure which shows the 1st conveyance paddle which concerns on this invention. It is a figure which shows the shape of the communicating port which concerns on this invention 1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention. 2A and 2B are schematic diagrams illustrating a configuration of a communication port in the developing device of the present invention, in which FIG. 3A illustrates a configuration on a developing unit side, and FIG. 3B illustrates a configuration on a toner cartridge side. It is a figure which shows the evaluation apparatus of a toner charge amount. It is a figure which shows the evaluation result of the toner charge amount of an Example. It is a figure which shows the evaluation result of the toner charge amount of a comparative example. It is a figure which shows the evaluation result of the toner charge amount of an Example. It is a figure which shows the evaluation result of the toner charge amount of a comparative example. FIG. 6 is a diagram illustrating a ratio of low reverse charge toner at the time of replacement with a new toner cartridge. FIG. 6 is a diagram in which collected toner is divided into charged areas. It is a figure which shows the result when 4 cycles are implemented.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 11 Photoconductor 12 Photoconductor cleaning unit 13 1st charging means 14 Drive roller (photoconductor)
15, 16 Followed roller (photosensitive member)
20 exposure means 21 registration roller 25 paper feed roller 26 contact / separation mechanism 30 developing device 31 developing unit 31a developing sleeve 31b supply roller 31c regulating roller 31d first transport paddle 31e slide shutter 31f elastic member 31g window 311 comb-like film 312 rectangular Shape film 32 Toner cartridge 321 First storage chamber 322 Second storage chamber 32a Second transport paddle 32b Third transport paddle 32c Slide shutter 32d Elastic member 32e Fixed seal 33 Communication port 34 Control valve 34a Support section 34b Film 35 Rib 40 Intermediate transfer Belt unit 41 Intermediate transfer belt 42 Belt cleaning unit 43 Mark sensor 44 Drive roller (intermediate transfer belt)
45 Primary transfer bias rollers 46, 47 Followed roller 49 Belt position detection mark 50 Secondary transfer unit 51 Secondary transfer bias roller 60 Fixing means 70 Double-sided transport device 80 Paper feed device 81 Paper feed roller 83 Manual feed tray 90 Transfer material 101 Electrode 102 Particle inlet 103 Photoelectric amplifier tube 104 Signal processing device 105 Focus lens 106 Particle outlet 107 Measurement area 108 Earth 109 Laser beam 110 Automatic thermal plate

Claims (11)

A developing unit for developing the latent image on the image carrier with toner;
In a developing device in which a toner cartridge for supplying toner to a developing unit is arranged in parallel, and the toner cartridge is detachable,
The developing unit has a first transport paddle for stirring the toner,
The toner cartridge has a second transport paddle for stirring the toner, and a rib is provided on the bottom of the inner wall surface of the toner cartridge.
A communication port that allows toner to pass by communicating the developing unit and the toner cartridge; and a control valve that is provided corresponding to the communication port and controls the amount of toner that passes through the communication port.
The first transport paddle has a plurality of paddle films,
The control valve swings from a fixed position in which the communication port is opened to a closed operating position by abutting with the paddle film of the first transport paddle, and from the operating position to the fixed position. By swinging back, the first space portion that opens to the communication port is formed on the downstream side in the moving direction,
The second transport paddle has at least one elastic film;
When the elastic film makes contact before Symbol rib by rotation, the toner is dammed between the and the elastic film ribs, then when the elastic film is further rotated, together with the ribs prevent the conveyance of the toner The elastic film lifts the toner in the front in the rotational direction, thereby forming a second space on the downstream side in the moving direction;
After the second space portion is formed, the control valve is returned to a fixed position by releasing contact with the paddle film of the first transport paddle, thereby forming the first space portion. The toner near the communication port lifted by the elastic film is supplied from the toner cartridge side to the developing unit through the communication port,
After the toner in the vicinity of the communication port is supplied to the developing unit, the second space portion opens toward the communication port, and then the control valve contacts the paddle film of the first transport paddle, The developing device according to claim 1, wherein the toner in the developing unit is discharged to the second space through the communication port by a control valve . The developing device according to claim 1,
2. A developing device according to claim 1, wherein the communication port has a rhombus shape . The developing device according to claim 1 or 2 ,
A developing device, wherein the adjacent control valves are driven alternately . In the developing device according to any one of claims 1 to 3,
The developing device according to claim 1, wherein each of the control valves includes a rigid support portion and an elastic operation portion . The developing device according to any one of claims 1 to 4,
The developing device characterized in that the width of the control valve is 0 mm to 20 mm larger than the width of the communication port . The developing device according to any one of claims 1 to 5,
2. A developing device according to claim 1 , wherein an interval between the control valves is 2 mm to 20 mm . The developing device according to any one of claims 1 to 6,
The developing device characterized in that the length of the control valve is 10 mm to 25 mm . The developing device according to any one of claims 1 to 7,
The developing device according to claim 1, wherein a valve angle at a fixed position of the control valve is 20 ° to 45 °, and a valve angle at an operating position is 0 ° to 15 ° . An image carrier that carries a latent image, a charging device that uniformly charges the surface of the image carrier, an exposure device that writes an electrostatic latent image on the surface of the charged image carrier, and a surface formed on the surface of the image carrier. A developing device that visualizes the electrostatic latent image, a transfer device that transfers the visible image on the surface of the image carrier directly or via an intermediate transfer member, and a cleaning that cleans the toner on the image carrier In an image forming apparatus comprising an apparatus and a fixing device that fixes a visible image on a recording member with heat and / or pressure,
The developing device according to claim 1 is used.
An image forming apparatus. The image forming apparatus according to claim 9.
The image carrier and the developing device are integrally supported, and a detachable process cartridge is provided.
An image forming apparatus. At least in the process cartridge that integrally supports the image carrier and the developing device and is detachable from the image forming apparatus main body,
The developing device according to claim 1 is used.
A process cartridge characterized by that.

Images