JP3492584B2 - Developing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device which can be used in a copying machine, a printer, a facsimile or the like which forms an image by electrophotography, and more particularly, can clean toner adhered to a toner layer regulating blade. It relates to a possible developing device.

[0002]

2. Description of the Related Art A one-component developing device that does not use a carrier is
Since the device has a simple structure and can be manufactured at a low cost, the device can be downsized, which is advantageous in terms of cost and maintenance. In particular, since a magnetic roller is not used, there is an advantage that a developing device that is compact and capable of forming a clear image can be obtained at low cost. Further, since the toner does not contain a magnetic material, it is also suitable for colorization. . In addition, in the one-component developing device,
As the developing method, a contact developing method in which development is performed while contacting with a photoconductor and a non-contact developing method in which development is performed in non-contact with the photoconductor are known.

In general, the one-component developing method depends on whether the toner is magnetic or non-magnetic, and whether it is in contact with the toner or not.
A thin layer of a predetermined charged one-component toner is formed on a developer carrier regardless of whether it is in non-contact, and the thin layer is formed with the rotation of the developer carrier to form a latent image on the photoreceptor. The latent image on the photoconductor is visualized (developed) by being conveyed to a developing position opposite to. At this time, in order to obtain a good image,
It is important to perform uniform charging on the developer carrier to stably form a thin toner layer having a uniform layer thickness. The charging and thin layer formation of the toner layer on the developer carrying member are generally performed by a toner layer regulating blade pressed against the developer carrying member with a predetermined pressure. However, even if a good toner thin layer can be formed initially, toner sticking to the blade may occur during long-term use, and a good toner layer may not be formed, leading to image deterioration. That is, the blade is kept in contact with the developer bearing member at a predetermined pressure, and in the contact nip where the blade comes into contact with the developer bearing member due to environmental factors such as frictional heat and its pressure, or machine temperature. The toner adheres (fixes) to the blade surface in the vicinity of the position. Initially, the adhered matter is a little like a thin film is put on the surface,
Although it does not cause any problem on the image, it grows as it is used, and eventually it adversely affects the image.
That is, the adhered matter causes deterioration of the charging property of the toner by the blade, clogging of the toner inflow opening between the developer carrier and the mechanical contact surface of the developer carrier. Unevenness, resulting in a total or local decrease in toner layer pressure and a local slip-through (increase in layer thickness),
It becomes impossible to form a uniform toner layer. As a result, a decrease in density on the image, partial white streaks, partial black streaks (in the case of monochrome), and the like occur.

In order to solve the above problem, a method of cleaning the toner adhered matter on the blade has been proposed. For example, in Japanese Patent Laid-Open No. 7-168440, a slidable fixed toner removing member is provided between a developer carrying member and a blade, and a method of removing the fixed toner particles by sliding the member, or a blade is described. A method is shown in which the developer is slidable in the vertical direction along the developer carrier, and a blade is slid up and down to remove adhered substances.

However, if the removing member is sandwiched between the developer carrying member and the blade and slid, both the surface of the blade and the surface of the developer carrying member are rubbed, which may damage both. Generally, the blade is several tens of gf / cm to the developer carrying member, and in some cases several hundreds gf / cm.
Pressed with a linear pressure of / cm. During this time, it is not easy to slide the inserted removal member so as not to damage the blade or the developer carrier. In the technique of the above publication, the end portion of the removing member is precisely finished, but it is very expensive. Further, in order to prevent scratches on the blade surface and the surface of the developer carrying member, it is necessary to move the blade straight so that it does not get caught in the sliding movement and the surface does not sag. Thus, in the above method, the blade adhered matter can be removed, but as a result of moving the removing member while contacting it, the developer carrier or the blade surface is easily damaged, and the cost also increases.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and facilitates cleaning of a toner layer regulating blade in a developing device, and at the time of cleaning, the blade surface or the surface of a developer carrying member. It is an object of the present invention to provide a means for reliably cleaning a blade without damaging the blade.

[0007]

As a result of intensive studies, the inventors of the present invention have found that the vicinity of the contact end of the toner layer regulating blade with the developer carrying member is opposite to the surface in contact with the developer carrying member. The present invention has been completed by finding that the above-mentioned problems can be solved by providing a cleaning member that is in sliding contact with the surface on the side while rotating and is cleaned.

That is, according to the present invention, a developer carrier for holding and transporting toner on a rotatable cylindrical surface, a toner supplying means for supplying one-component toner, and a toner abutting on the surface of the developer carrier for pressing, In a developing device having a toner layer regulating blade that regulates the layer thickness while charging the
A developing member provided with a cleaning member for cleaning the blade in the vicinity of the contact end of the blade with the developer carrying member while rotating and slidingly contacting the surface opposite to the surface contacting with the developer carrying member while rotating. Regarding the device.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of a cleaning member used in the developing device of the present invention is, for example, a structure in which an elastic member or the like is provided around a shaft body made of metal, resin or the like by means of fitting or the like. It is preferable that The shape of the cleaning member is preferably, for example, a cylindrical shape, a rotating spiral shape, or the like. Further, the outer surface of the cleaning member has, for example, a shape in which grooves parallel to the axial direction are cut, a shape in which grooves are cut in a spiral shape, a shape with a brush, a shape with a paddle, a shape with a pad, etc. be able to. Examples of the material of the outer surface of the cleaning member include urethane, silicon, NBR (nitrile-butadiene rubber), EPDM
It is preferable to use a foamed foam such as (ethylene-propylene-diene copolymer rubber). Also in the case where the paddle is provided on the outer surface, the same material as described above can be used. Further, in the case where the outer surface is provided with a brush, it is preferable to use a chemical fiber such as nylon or rayon as the material of the brush. Further, in the case where the pad is provided on the outer surface, as the material of the pad, for example, an elastic rubber member such as urethane or silicon, or a soft elastic member such as felt is preferably adopted.

The outer diameter of the cleaning member can be set as appropriate, but is preferably about 10 to 20 mm, for example. The length of the cleaning member in the longitudinal direction is preferably set to be substantially the same as the length of the toner layer regulating blade in the longitudinal direction.

In the developing device of the present invention, the cleaning member has a portion near the portion where the toner layer regulating blade contacts the developer carrying member (that is, the contact portion and its peripheral portion).
In, the blade is slidably contacted from the opposite side (back side) of the surface where the blade contacts the developer carrying member. Here, the depth of penetration of the cleaning member into the toner layer regulating blade and the developer carrying member is preferably set to about 0.5 to 1 mm, for example.

The rotation direction of the cleaning member may be the same as or opposite to the direction of the developer carrying member, but the vicinity of the abutting end between the toner layer restricting blade and the developer carrying member is separated from the support of the toner layer restricting blade. It is preferable that the sliding contact is made in the contact end direction. The rotation speed of the cleaning member is preferably, for example, about several tens mm / sec in peripheral speed.

The developing device of the present invention is, for example,
It can be applied to an image forming apparatus equipped with a counting means for counting the operating time, the number of revolutions of the developer carrier, etc., and the sliding contact cleaning operation is performed when the count value by the counting means reaches a predetermined value. The developing device is preferably used as a developing device. Further, the developing device of the present invention performs image adjustment so that an optimum print image is obtained when the power is turned on, when a predetermined number of prints is reached, when returning from the energy saving mode, and the like.
The present invention can be applied to an image forming apparatus having a function of controlling process conditions, and can be suitably used as a developing apparatus that performs a sliding contact cleaning operation before or simultaneously with the image adjustment. The cleaning of the blade tip by the cleaning member is preferably performed immediately before supplying new toner into the developing tank.

In the developing device of the present invention, the cleaning member cleans the surface of the supply roller simultaneously with the cleaning operation.
Alternatively, the sliding operation may be performed separately from the cleaning operation. When the cleaning member is not cleaned, the cleaning member has a predetermined distance from the contact portion between the blade and the developing roller (preferably about several mm to 30 mm).
It is preferable that they are arranged adjacent to each other at a distant position. further,
It is preferable that the cleaning member is rotatably supported and contacts the developing roller during cleaning so that the cleaning member rotates in association with the rotation of the developing roller.

FIG. 12 is a diagram illustrating an outline of a general structure of a one-component developing device to which the present invention can be applied. The toner contained in the toner tank (hereinafter abbreviated as “hopper”) of the developing device is, for example, a developer carrier (hereinafter referred to as “developing roller”) by means such as an agitator or a screw.
It will be abbreviated as 100). Developing roller 10
0, the toner supply roller 200 is in pressure contact with the developing roller 100.
The same direction, that is, the moving directions of the surfaces of both rollers in the portion facing the developing roller 100 are opposite to each other. A voltage is applied to the toner supply roller 200 from a bias power source 210, and the voltage acts in a direction to electrically push the toner toward the developing roller 100. For example, if the toner is a negative polarity toner, A large bias voltage is applied to the negative electrode side.

The toner which is frictionally contact-charged by the toner supply roller 200 and is supplied to the developing roller 100 by the bias voltage is subjected to a toner layer regulating blade (hereinafter abbreviated as “blade”) 300 by the rotating operation of the developing roller 100. It is transported to the abutting position. Toner layer regulation blade 300 made of a plate-shaped metal material or the like
Has one end supported, and the abdomen at the other end (tip or in the vicinity of the tip) is elastically pressed against and abutted on the developing roller 100. Depending on a predetermined set pressure and set position, the developing roller 1
The toner on 00 is regulated to have a predetermined charge amount and a predetermined thickness, and the developing area (that is, the photosensitive member 51 on which the electrostatic latent image is formed).
And a developing process.

Developing roller 1 not used in the developing process
The undeveloped toner on 00 returns to the developing device by the rotation of the developing roller 100, but is charged by the charge removing device / means 400 of the toner on the developing roller 100 installed in front of the toner supply roller 200 after the developing area. The charge is removed, and the toner is separated and collected in the hopper by the pressure contact at the entrance of the toner supply roller 200, and is reused.

Table 1 shows an example of a more specific device configuration and various conditions of the developing device to which the present invention can be applied.

[0019]

[Table 1]

In FIG. 12, reference numeral 51 indicates a diameter Da = 3 in which the conductive base material is grounded and the surface potential is charged to −550V.
It is a negatively charged photosensitive drum of 0 mm and has a peripheral speed V in the direction of the arrow.
It rotates at a = 150 mm / s. The conductive elastic developing roller 100 has a diameter Db of 20 mm and has a volume resistivity of about 1 to which a conductive agent such as carbon black is added.
0 ⁶ Ωcm, JIS-A hardness consist 60-70 degrees conductive urethane rubber, the peripheral speed in the direction of the arrow Vb = 225 mm / s
E1 = -300 by the developing bias power supply 110 through a shaft of a conductive support (for example, stainless steel, conductive resin, etc.) having a diameter Ds = 10 mm.
A voltage of V is applied to the photosensitive drum 51 via a toner layer so that the developing nip width is about 1.5 mm.

A supply roller 200 having a diameter of 16 mm and made of a conductive urethane foam having a volume resistivity of about 10 ⁵ Ωcm and a cell density of about 3 cells / mm, which serves to both agitate the toner and remove the toner after development, has a contact depth of 0. Development roller 1 with 5 to 1 mm
00, is rotating at a peripheral speed Vc = 133 cm / s in the direction of the arrow, and a voltage of E2 = −400 V is supplied by the supply bias power supply 210 via the shaft of the conductive support (stainless steel, conductive resin, etc.). Is being applied.

The non-magnetic one-component toner, which is negatively precharged by the supply roller 200 and applied on the surface of the developing roller 100, is conveyed to the position where the toner layer regulating blade 300 comes into contact with the rotation of the developing roller 100. The toner layer restriction blade 300 is a conductive plate member having a thickness of 0.1 mm (for example, stainless steel, phosphor bronze, conductive resin, etc.), and a cantilever plate spring having a free end on the upstream side in the rotation direction of the developing roller 100. Due to the structure, the developing roller has a linear pressure of about 15
It is abutting at ~ 30 gf / cm. Further, the toner layer regulating blade 300 is applied with a voltage of E3 = −400V by the toner layer regulating blade bias power source 390. The toner layer on the developing roller 100 is adhered by the elastic toner layer regulating blade 300 to a toner adhesion amount of about 0.6 to 0.
8 mg / cm ² , toner charge amount of about −10 to −15 μC /
After being regulated to g, the developing roller 100 is rotated to convey it to a developing area in contact with and oppose the photoconductor 51 to perform contact reversal development.

In FIG. 12, reference numeral 400 indicates the developing roller 10.
The toner charge removing unit 400 is a seal for preventing leakage of toner from below, and at the same time, removes the charge of undeveloped toner on the developing roller 100 after development.
The toner charge removing unit 400 uses a conductive film having a thickness of 0.2 mm, and is set to the same potential as the developing roller 100 or a potential higher than the developing roller by about +50 V or more by the bias power supply 410 for the toner charge removing unit. The conductive surface is brought into contact with the developing roller 100. As the toner charge removing means 400, for example, a conductive member such as an aluminum vapor deposition film can be adopted. However, when it is not necessary to remove the toner charge and only the lower seal is intended, for example, a Mylar A film or the like may be used, and in this case, the bias power source 410 for the toner charge removing means is not necessary.

The toner used in the developing device is preferably one generally called high resistance toner. More specifically, the electrical resistance of pellets is about 10 ¹⁰ Ω · c.
As a base resin, a resin such as polyester resin or styrene-acrylic copolymer is used in a range of 80 to 90 m.
Parts by weight, carbon black of about 4 to 10 parts by weight,
After kneading, mix 0 to 5 parts by weight of the charge control agent (CCA) and an appropriate amount of the vulcanization control agent (a minute amount), and after the pulverizing step, for example, about 0.2 to 2 parts by weight of an external additive such as silica. A mixture is exemplified.

[0025]

EXAMPLES Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the invention. Embodiment 1 FIG. 1 is a schematic sectional view showing an embodiment of a developing device of the present invention, and FIG. 2A is a schematic view showing the shape of a cleaning member 700 used in this embodiment. . The cleaning member 700 has a diameter of 12 m in which the outer surface of a shaft 701 made of a metal cored bar or resin is covered with foam.
The sponge roller is about m, and is retracted upward during the non-cleaning operation. In this embodiment, the same material as the supply roller 200 is used as the foamed foam, but the foamed foam is not limited to this.

During cleaning, the cleaning member 7
00 is disposed in the vicinity of the contact portion between the layer regulation blade 300 and the developing roller 100, that is, at a position where the free end of the blade and a portion including the surface of the developing roller are in sliding contact with each other. Same direction as the roller (Fig. 1
Rotate counterclockwise). Here, the biting depth of the cleaning member 700 with respect to the layer regulating blade and the developing roller was set to about 0.5 to 1 mm. The cleaning member 700 is in the same direction as the developing roller 100 (see FIG.
By rotating in the counterclockwise direction), the vicinity of the contact portion between the layer-regulating blade and the developing roller is slidably cleaned from the surface opposite to the surface of the blade contacting the developing roller. After the cleaning is completed, the cleaning member retreats to the upper retreat position.

By the way, the toner supplied by the supply member 200 upstream in the rotation direction of the developer carrying member is regulated in layer thickness at the blade edge portion, and excess toner returns to the developing tank. Toner adheres to the blade edge portion due to use over time, and if the adhered toner is sequentially replaced, no problem occurs, but the same toner may stagnate for a long period of time. Toner that has once stagnated is not easily replaced and tends to stay stagnant forever. Since the toner which is regulated by the blade flows in from the upstream one after another, the staying toner is adhered in a considerably solidified state as a result of being continuously subjected to the powder pressure of the toner.
In addition, as a result of being pressed and solidified, it is difficult for extra replacement to occur.

In the present invention, the adhering toner is removed by the rotary sliding contact operation of the cleaning member, and the removed toner is returned to the hopper and reused again with other toner. Also, since the adhered toner is considerably pressed and solidified, it is also integrated with the toner that adheres to the blade contact surface side and is similarly clogged. By removing the toner, it is possible to remove the toner on the contact surface side as a unit. At this time, the clogging of the staying toner is not so strong, and therefore, the integrity with the adhering matter on the blade contact surface side cannot be obtained, and only the adhering toner on the back surface of the blade is removed, and the adhering toner on the abutting surface side is removed. Even if it cannot be removed, it is not a level that immediately leads to image deterioration because the pushing pressure is low, and there is no problem if it can be removed by cleaning after the next time.

On the other hand, in some cases, not only the toner is pressed and solidified on the blade contact surface, but also adhered matter which is transformed and strongly adhered due to frictional heat or pressure is generated and grown. . In such a case, the adhered matter usually grows so as to project from the blade edge, and a part of the adhered matter is visible from the back surface of the blade edge (although actually Not directly visible because it is buried in the toner not). If this is removed from the back surface of the blade by the cleaning member 700,
It is possible to remove the entire solidified matter.
Further, the toner adhered matter normally continues to receive pressure from the upstream side due to the rotation direction of the developer carrier, but particularly in the case of this embodiment, the blade 300 has a configuration in the leading direction, and goes from the downstream side to the upstream side. Since the cleaning member is slidably moved in the direction, the entire adhered matter is easily removed as a unit. Of course, even in the case of the trailing structure, the effect of integrally removing the adhered matter can be obtained. As described above, although the cleaning effect can be obtained even when the fixing progresses, it is preferable to remove the staying toner before the fixing progress to delay the occurrence of the fixing itself.

In Table 2, when cleaning is performed by the cleaning method of this embodiment, no cleaning is performed, and a mylar member (thickness: 0.2 mm) is inserted between the developing roller 100 and the toner layer regulating blade 300. Then, the results of a printing test when cleaning is performed by reciprocally sliding in the axial direction of the developing roller (conventional method) are shown. The numbers in the table indicate the number of white streak lines caused by toner sticking to the blade or the inclusion of foreign matter. The numbers before and after cleaning are also shown (before cleaning / after cleaning). The number of printed sheets 1k means 1,000 sheets, and 5k means 5,000 sheets.

[0031]

[Table 2]

According to this embodiment, a good image without white lines was obtained for a long period of time. It was also found that it is more effective to carry out cleaning regularly.
For comparison, as a conventional method, a plate-like cleaning member (PET film having a thickness of 0.2 mm and a width of 20 mm) was sandwiched between the developer bearing member and the contacting side surface of the toner layer regulating blade, and the developer bearing shaft was inserted. A cleaning method of manually reciprocating in one direction was carried out. In this conventional method, it was not easy to sandwich the cleaning member between the developer carrying member and the toner layer regulating blade pressed against the developer carrying member and slide the cleaning member. Further, in the conventional method, the surface of the developer carrying member is damaged by the sliding of the cleaning member, and the image on the developing roller pitch is stained due to the scratch on the surface of the developing roller. This stain was often cleaned every 1 k for the same number of prints. Therefore, in the conventional method, if the cleaning frequency is increased, it is possible to prevent image deterioration due to toner adhesion, but it is clear that the probability of damage to the developing roller increases. On the other hand, in the case of this embodiment,
Sliding the back surface of the blade with a sponge roller also has the effect of removing adhered toner, does not cause damage to the blade contact surface or the developing roller surface, and does not cause image contamination due to damage to the developing roller surface. It was

As the tip shape of the blade 300 to which the cleaning method of the present invention can be applied, as shown in FIG. 3 (a), from the shape shown in FIG. It is also possible to use a blade having various inclined portions at its tip as exemplified in e). That is, the present invention is effective in a configuration in which the plate-shaped layer thickness regulating blade is brought into contact with the surface of the developing roller at the tip edge or near the edge regardless of the tip shape of the blade.

Although urethane foam is used as the material of the cleaning member 700 in this embodiment, for example, silicon, NBR (nitrile-butadiene rubber), EPD is used.
Foamed foams of various resin materials such as M (ethylene-propylene-diene copolymer rubber) can also be used. Alternatively, a roller having a layer of a soft elastic member such as felt formed on the surface may be used.

Further, regarding the shape of the cleaning member,
In the present embodiment, a cylindrical outer surface was used as illustrated in FIG. 2A, but other than this, a groove parallel to the axial direction as illustrated in FIG. 2B was cut. Alternatively, the groove may be cut in a spiral shape as illustrated in (c). In this case, an intermittent force can be applied to the adhered matter of the blade due to the groove, and there is an effect of removing by an impacting force.

Further, as shown in FIG. 4, a brush shape can be applied. As the material of the brush, for example, a chemical fiber such as nylon or rayon can be used, and the fiber diameter is preferably about 0.05 mm to 0.5 mm. FIG. 4 (a) is an example of a brush having an outer diameter of 12 mm and a bristle length of 2 mm, and FIG. 4 (b) is a brush having a brim of 4 mm, which is subjected to bevel treatment to have an outer diameter of 12 mm. It is a slanted brush.

Further, the shape of the cleaning member may be a paddle shape as illustrated in FIG. 5 (a). In this case, as the paddle blade 704, for example, a rubber material typified by urethane, silicon, NBR, EPDM, or the like, or an elastic material such as a resin sheet typified by PET, or the like can be used. The contact with the vicinity of the toner layer regulation portion is at a position where the blade is slightly deflected, that is,
For example, it is preferable to arrange them so as to have a recess depth of about 0.5 to 0.1 mm. Also in this case, the blade edge portion can be intermittently brought into sliding contact. Fig. 5 (b)
Is a column in which a pad 705 is attached in the cylindrical surface direction to the tip of a column extending radially from the shaft. As the pad, for example, an elastic rubber member typified by urethane, silicon, or the like, or a felt or the like is typified. A soft elastic member can be used.

Embodiment 2 FIG. 6 is a schematic view showing another embodiment of the cleaning member of the present invention. Here, an example in which a spiral structure as shown in FIG. 6 is used as the rotating cleaning member 700 is shown. In this spiral structure, a resin molded body 702 having a spiral-shaped convex portion is formed on the outside of a metal cored bar, and a foamed foam member is attached to the outer peripheral surface portion 703 thereof. For example, about 12 mm is preferable. During the cleaning operation, the cleaning member is pressed and brought into contact with the vicinity of the contact portion between the toner layer regulating blade and the developing roller with a predetermined amount of depression or a predetermined pressure, and is rotated by an arbitrary drive mechanism. The direction of rotation is preferably the direction in which the edge portion of the toner layer regulating blade slides from the supporting end side of the blade toward the edge (free end) side. In the case of the present embodiment, the bite depth is about 0.
The cleaning member is adjusted to 5 mm and the contact of the toner layer regulating blade is a leading structure, so that the cleaning member rotates in the same direction as the developing roller (counterclockwise in FIG. 1).

Since the cleaning member has a spiral structure, the outer peripheral portion of the edge tip at the longitudinal position of the toner layer regulating blade is slidably contacted only once per rotation. That is, the rotation of the cleaning member causes intermittent sliding contact. In addition, due to the helical structure during sliding contact, a force is also applied in the longitudinal direction, and the deposits on that portion can be effectively removed. Furthermore, as the cleaning member of the spiral structure rotates, the part in contact with the blade edge moves sequentially,
The deposits are also removed in order. At this time, since a force is applied to the adhered matter from the side after the removal, the adhered matter can be removed in a chain.

In this embodiment, the outer peripheral surface portion 70 of the spiral body is used.
Although foamed foam is attached to 3, a soft elastic body typified by felt or the like, or an elastic resin typified by urethane rubber or the like may be used. The helical structure is 1
The structure is not limited to the double helix, but may be, for example, a double or triple helix structure. In this case, the cleaning member 1
It is possible to make sliding contact twice or three times for each rotation.

Embodiment 3 FIG. 7 is a schematic flow chart showing an example of the operation of the cleaning member in the developing device of the present invention. In this example, the developing device of the present invention is applied to an image forming device having a counting means for counting the number of printed sheets. When a certain printing operation is completed (step 1, step 2), the number of printed sheets after the previous cleaning, that is, the numerical value of the cleaning control printed sheet counter is incremented by 1 (step 3). Next, it is compared and judged whether or not the numerical value of the counter reaches a predetermined number determined in advance (step 4). As a result, when it is determined that the predetermined number has been reached, a blade cleaning operation signal is issued and the blade cleaning operation is performed (step 5). If cleaning is completed,
The cleaning control sheet counter is cleared to 0 (st
ep6), return to the READY state. With this setting, the blade can be cleaned every predetermined number of prints, and a good image can be maintained for a long period of time.

In this embodiment, the cleaning operation is performed with a fixed number of prints, but the cleaning operation may be performed by counting the moving time of the apparatus or the rotation time of the developing roller, or a combination of these. You may go. Further, for example, it is possible to set the cleaning to be performed when any one of them reaches a predetermined value, or conversely, to set the cleaning to be performed when a plurality of count values reach a predetermined value. May be. Further, the number of times cleaning is performed may be counted, and the predetermined value may be changed accordingly. For these, an optimal method can be appropriately selected.

Embodiment 4 FIG. 8 is a schematic flow chart showing the operation of the cleaning member in another embodiment of the present invention. In this example, it is applied to an image forming apparatus having an image adjusting function so that an optimum image can be obtained even when the environment is changed or long-term use. Turning on the main power switch of the image forming apparatus main body (step
After p1), the blade cleaning operation (step 2)
I do. After that, image adjustment is performed (step 3).
For example, the test pattern is developed, the developed image is sensed by the density sensor, and the amount of deviation from the reference density is determined. Based on the determination, the image forming condition is changed and controlled to be closer to the reference value. That is, this embodiment is an example applied to an apparatus that performs image adjustment when the power of the image forming apparatus main body is turned on, and is configured to clean the blade before performing image adjustment. Here, the timing of image adjustment is not limited to the time when the power is turned on. It is also applicable to an image device that performs adjustment. In other words, by performing cleaning of the blade before performing image adjustment, it is possible to perform image adjustment with the blade being cleaned, and perform good image adjustment even in environmental changes and long-term use. And good printing can be maintained.

Embodiment 5 FIG. 9 is a schematic view showing another embodiment of the developing device of the present invention. As the cleaning member 700, the same member as that of the first embodiment is used, and when cleaning the toner layer regulation blade, the same applies in that the vicinity of the contact portion between the toner layer regulation blade and the developing roller is slidably cleaned. The cleaning member of the present embodiment is brought into contact with the supply roller 200 at the same time as the blade cleaning or in another step to rotate in sliding contact. When the cleaning member abuts and rotates on the supply roller, the supply roller is also rotated. By this,
The clogging of the supply roller can be eliminated and refreshed, and the stability of toner layer formation and the followability during solid printing can be restored.

Embodiment 6 FIG. 10 is a schematic view showing still another embodiment of the developing device of the present invention. The cleaning member 700 is, for example, a urethane sponge roller having a diameter of 10 mm, and when the toner layer regulating blade is cleaned, the vicinity of the contact portion between the toner layer regulating blade and the developing roller is slidably cleaned. The cleaning member in this embodiment is arranged at a position a predetermined distance from the contact portion between the toner layer regulating blade and the developing roller during non-cleaning, that is, during normal printing operation. In the present embodiment, it is arranged at a position horizontally separated from the contact portion by about 2 mm.

The developing roller 100 is supplied by the supply roller 200.
The amount of charge and the layer thickness of the toner supplied to the toner are regulated by the toner layer regulating blade 300, and a uniform thin toner layer is formed on the developing roller 100. Toner layer control blade 3
The excess toner regulated by 00 is removed by the cleaning member 7
It goes around above 00 and is returned to the inside of the hopper. At this time, the flow path of the toner regulated by the blade to return to the hopper and the flow channel of the toner supplied by the supply roller before being regulated are clearly separated by the cleaning member 700. As a result, a smooth flow 800 of toner that is to be regulated and toner that has already been regulated is formed at the toner layer regulation portion, that is, the contact portion between the toner layer regulation blade and the developing roller. Can reduce the stress received by
It is possible to further suppress the toner sticking to the blade in the regulation portion. In the case of the present embodiment, the cleaning member is not rotated during non-cleaning, but it is also possible to more positively control the toner flow by rotating the cleaning member during non-cleaning.

Example 7 FIG. 11 is a schematic sectional view showing another embodiment of the present invention. The cleaning member 700 is rotatably held, and is pressed against the contact portion between the blade and the developing roller at the time of cleaning, but a mechanism (eg, motor, gear train, etc.) for driving the cleaning member itself is used. Is not particularly connected, and is rotated by the frictional force with the surface of the developing roller in conjunction with the rotation of the developing roller. In the case of the present embodiment, the blade has a trailing structure, and by rotating together with the developing roller, the sliding contact direction of the cleaning member is changed from the fixed end to the free end, so that the adhered (fixed) toner can be drawn out to a wider space. it can. Further, since the cleaning member can be pressed from the outside of the toner hopper, the cleaning member is not contaminated by the toner more than necessary, and the cleaning property can be maintained for a long time.

[0048]

According to the invention described in claim 1,
The risk of scratching the surface of the developer carrier and the blade contact surface is low, and by sliding the blade edge part from the back surface of the blade with a cleaning member, the toner that accumulates near the blade edge can be easily removed and retained. The condition can be resolved. That is, it is possible to eliminate the state where the toner continues to be stressed due to the retention, and as a result, it is possible to delay the generation or growth of the adhered matter (if the retention of the toner continues,
The same toner group will continue to be stressed, and eventually degenerate, leading to sticking).

Further, even when the adhered matter has already grown and has grown up to the point where it protrudes from the blade edge, the adhered matter is integrated with the contact surface side, so that this is applied from the back surface side. By removing, the whole adhered matter can be removed. As described above, by performing the sliding contact from the back side of the blade, the risk of damaging the blade contact surface and the developer carrier is much less than the method of sandwiching the cleaning member between the developer carrier and the blade. . Further, by rotating the cleaning member, it is possible to efficiently perform cleaning with softer contact. As a result, it is possible to eliminate or prevent white stripes, black stripes, and density decrease due to the adhered matter of the blade. At the time of cleaning, the rotation direction of the cleaning member is set so that the sliding contact direction with the vicinity of the blade end is directed from the blade fixed end (supporting end) side toward the free end (contacting end) side, thereby fixing the fixed object. Or push the deposit in an open direction with space (or
Can be pulled out), and the adhered matter or the adhered matter can be effectively removed.

According to the second aspect of the invention, the length of the cleaning member in the longitudinal direction is substantially the same as the length of the toner layer regulating blade in the longitudinal direction, so that the entire length of the blade is the same. Can be efficiently cleaned by operation.

According to the third aspect of the invention, the cleaning member is made of foamed foam (sponge) such as urethane, silicon, NBR, and EPDM so that the contact can be made softer and the contact nip can be widened. It is possible to obtain a high cleaning effect.

In the invention according to claim 4, the slidable contact direction is changed from the fixed end to the free end, whereby the adhered (fixed) toner can be drawn out in a wide space direction.
Further, both the leading structure and the trailing structure are applicable.

According to the fifth aspect of the present invention, by making the shape of the cleaning member cylindrical, the cleaning member can be slid evenly at any timing in accordance with the rotating operation of the cleaning member, and the cleaning can be efficiently performed.

According to the sixth aspect of the present invention, by making the cleaning member have a rotating spiral shape (screw shape), a force in a direction different from the rotating direction of the cleaning member is applied to an arbitrary cleaning portion on the blade. Can be added intermittently. Further, with the helical structure, cleaning is performed continuously in the blade longitudinal direction, and it is possible to continuously perform cleaning from a portion that is easily cleaned, such as a portion where toner adhesion is weak or adhesion is about to peel. .

According to the invention of claim 7, the cleaning of the blade is periodically performed, whereby the removal and growth of the adhered matter can be prevented for a long period of time, or the adhered matter itself can be prevented from being generated. In this way, it is possible to obtain an image in which white streaks and high-density streaks (black streaks) are not generated due to toner adhesion on the blade, or images in which the density is not reduced.

According to the invention of claim 8, the main developing device is applied to the image forming apparatus having the image adjusting function, and the blade is cleaned before the image adjusting operation, so that the toner adheres to the blade. It is possible to perform image adjustment by removing the image deterioration and obtain a better image. Further, by appropriately setting the timing of image adjustment, the blade can be regularly cleaned, so that it is possible to maintain a good image for a long period of time.

In the invention according to claim 9, the cleaning member rubs the surface of the supply roller,
The clogging of the supply roller can be eliminated, the adhered matter of the blade can be removed (prevented), and the supply performance can be recovered (prevention of deterioration), and a good image can be obtained for a long period of time.

According to the invention of claim 10, the blade can be cleaned at the timing of replenishing the developing tank with new toner, so that the cleaning can be carried out almost regularly. In addition, cleaning the blade when replenishing fresh toner that is not stressed is effective for recovering the charging property of the blade. When replenishing toner, the toner in the developing tank is almost exhausted and the toner is almost exhausted, and the amount of toner in the developing layer is relatively small (not full of toner). The cleaning operation by the cleaning member can be performed without any hindrance, and the blade tip deposits can be effectively removed.

According to the eleventh aspect of the present invention, the contact portion between the developing roller and the blade (at the time of non-cleaning (that is, at the time of normal operation) does not cause the rotary cleaning member to be completely withdrawn. By disposing a predetermined gap in the vicinity of the toner layer restriction portion), the flow of toner regulated by the restriction portion can be rectified along the cleaning member. As a result, the regulated toner can be returned to the hopper with a low stress. In addition, it is possible to prevent the toner layer from staying in the toner layer restriction portion, and to stably form the toner layer. Furthermore, this action can delay the occurrence of toner sticking to the blade, and even if sticking occurs, the adhered matter can be removed by the cleaning operation.

According to the invention of claim 12, the rotation of the cleaning member is made to rotate together with the contact with the developing roller, so that a mechanism such as a motor or a gear train for driving the cleaning member can be omitted. .

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a developing device of the present invention.

FIG. 2 is a schematic view showing an example of the surface shape of the cleaning member of the present invention.

FIG. 3 is a schematic view showing an example of a sectional shape of a toner layer regulating blade of a developing device to which the present invention is applied.

FIG. 4 is a schematic view showing an example of an implementation shape of a cleaning member of the present invention.

FIG. 5 is a schematic view showing an example of an implementation shape of a cleaning member of the present invention.

FIG. 6 is a schematic view showing an example of an implementation shape of a cleaning member of the present invention.

FIG. 7 is a flowchart showing cleaning timing in the developing device of the present invention.

FIG. 8 is a flowchart showing cleaning timing in the developing device of the present invention.

FIG. 9 is a schematic sectional view showing an embodiment of the developing device of the present invention.

FIG. 10 is a schematic cross-sectional view showing an embodiment of the developing device of the present invention.

FIG. 11 is a schematic sectional view showing an embodiment of a developing device of the present invention.

FIG. 12 is a schematic sectional view showing an example of a developing device to which the present invention can be applied.

[Explanation of symbols]

1: Development unit (development tank) 51: Photosensitive drum 100: developer carrier 110: Development bias power supply 200: Supply roller 210: Supply roller bias power supply 300: Toner layer control blade 390: Bias power supply for toner layer regulation blade 400: Toner charge removing means 410: Bias power supply for toner charge removing means 700: Cleaning member 800: Toner flow

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mikie Kobayashi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Masahiro Sakai 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Sharp shares In-house (72) Inventor Shigeyuki Wakata 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/08

Claims (12)

(57) [Claims] 1. A developer carrier for holding and transporting toner on a rotatable cylindrical surface, toner supply means for supplying one-component toner, and pressing contact with the surface of the developer carrier to charge the toner. In a developing device having a toner layer regulating blade that regulates the layer thickness together, the vicinity of the contact end of the blade with the developer carrying member is rotated from the surface opposite to the surface in contact with the developer carrying member. The developing device is provided with a cleaning member that is in sliding contact with and is cleaned. 2. The developing device according to claim 1, wherein the length of the cleaning member in the longitudinal direction is substantially the same as the length of the toner layer regulating blade in the longitudinal direction. 3. The outer surface of the cleaning member is composed of a foamed foam selected from the group consisting of urethane, silicon, nitrile-butadiene rubber (NBR) and EPDM (ethylene-propylene-diene copolymer rubber). The developing device according to claim 1 or 2. 4. The rotation direction of the cleaning member is a direction in which the vicinity of the contact end between the toner layer restriction blade and the developer carrying member slides in the contact end direction from the support of the toner layer restriction blade. The developing device according to claim 1, wherein the developing device is a developing device. 5. The developing device according to claim 1, wherein the cleaning member has a cylindrical shape. 6. The developing device according to claim 1, wherein the cleaning member has a rotating spiral shape. 7. A developing device applied to an image forming apparatus, wherein the developing device is provided with a counting means for counting the number of printed sheets, an operating time, or the number of revolutions of a developer carrier, and the count value by the counting means. 7. The developing device according to claim 1, wherein the sliding contact cleaning operation is performed when is a predetermined value. 8. The developing device has a function of performing image adjustment so as to obtain an optimum printed image when the power is turned on, when a predetermined number of printed sheets is reached, or when returning from an energy saving mode, and a function of controlling process conditions. The developing device according to claim 1, wherein the sliding contact cleaning operation is performed before or simultaneously with the image adjustment, which is applied to the image forming apparatus. 9. The developing device according to claim 1, wherein the cleaning member is also used for slidingly contacting the surface of the supply roller. 10. The developing device according to claim 1, wherein the cleaning of the blade tip by the cleaning member is performed immediately before supplying new toner into the developing tank. 11. The cleaning member is arranged at a position apart from a contact portion between the blade and the developing roller at a predetermined interval when the cleaning member is not cleaned.
11. The developing device according to any one of 1 to 10. 12. The cleaning member is rotatably supported and contacts the developing roller during cleaning, whereby the cleaning member rotates in association with the rotation of the developing roller. The developing device described in the item.