JP2000141732A - Image-forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably form images by surely preventing a pass hole from being clogged. SOLUTION: At least a sleeve for holding and transferring a charged toner, an FPC(flexible print circuit) 17 which has a developer pass hole array 17g where a plurality of developer pass holes passing the toner are arranged in an array and which controls the passing of the toner supplied from the developer hold means in accordance with image signals from outside, and an image- receiving means to which a developer passing the developer pass holes adheres are provided in this order in the image-forming apparatus. A rod-shaped vibrating body 6 extending along the developer pass hole array is set on the FPC, and vibrators 61, 61 are arranged to both sides of the vibrating body. A voltage is impressed to the vibrators, thereby vibrating the vibrators. The vibration is transmitted to the FPC via the vibrating body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a facsimile, and a printer, and more particularly to an image forming apparatus for forming an image on a recording medium by causing a powdery developer to fly by the action of an electric field.

[0002]

2. Description of the Related Art Conventionally, there has been known an image forming apparatus which forms an image on a recording medium by causing a powdery developer to fly by the action of an electric field. In this apparatus, a head in which toner as a developer is stored, an intermediate image holding belt disposed opposite to the head, and an image formed on the intermediate image holding belt are transferred onto recording paper. It comprises a transfer unit and a fixing unit for fixing the image on the recording paper.

As shown in FIG. 15, the head 1 has a sleeve 11 carrying toner charged to a negative charge, and a developer passage control means for controlling the passage of the toner carried on the sleeve 11. A passing member 17 which is one of the components is provided. A row of developer passage holes is formed in the passage member 17, and a control electrode 17b is arranged so as to surround the periphery of each developer passage hole 17a constituting the row of developer passage holes. Further, a back electrode 23 is provided at a position facing the head 1 with the intermediate image holding belt 2 interposed therebetween.

In the image forming apparatus, an electric field is generated by applying a voltage to the control electrode 17b, and the toner carried on the sleeve 11 is caused to fly by the action of the electric field. The flying toner passes through the developer passage hole 17a, and after passing through the developer passage hole 17a, is pulled by the electric field formed by the back electrode 23 and adheres to the intermediate image holding belt 2. By controlling the voltage applied to the control electrode 17b in this manner, the flying of the toner is controlled, and an image is formed on the intermediate image holding belt 2.

[0005]

However, in the above-described conventional image forming apparatus, while the image formation is continued, FIG.
As shown in FIG. 6, toner accumulates around the sleeve 11 side of the developer passage hole 17a, the inner wall of the developer passage hole 17a, or around the intermediate image holding belt 2 of the developer passage hole 17a. And finally, the developer passage hole 1
7a is blocked by the toner.

The present invention has been made in view of such circumstances, and an object of the present invention is to reliably prevent blockage of a passage hole and realize stable image formation.

[0007]

The present inventor has completed the present invention by focusing on the following points.

That is, the size of the toner is usually 10 μm.
The diameter of the developer passage hole is set to 50 to 200 μm. However, the above toner does not always exist as one toner, and there are cases where several toners are collected and exist as a toner group having a size of several tens of μm. As described above, in the case of the toner group, it becomes difficult to charge all the toner carried by the sleeve 11 and charged by frictional charging to a uniform negative charge. Will occur. In such a case, for example, the toner that is not charged to a negative
Even if the developer passes through the developer passage 7a, the developer is not pulled by the electric field generated by the back electrode 23, and adheres to the periphery of the developer passage hole 17a on the intermediate image holding belt 2 side.

Further, the toner flying by the electric field formed by the control electrode 17b includes not only the toner existing at the position facing the developer passage hole 17a but also the toner around the toner. In this case, the toner that flies from the surroundings flies toward the developer passage hole 17a.
Not all the toner can pass through the developer passage hole 17a, and a part of the toner may adhere to the periphery of the developer passage hole 17a on the sleeve 11 side or the inner wall of the developer passage hole 17a. . In such a case, if the toner group is present, since the toner group has a large diameter, the toner group adheres to the periphery of the developer passage hole 17a on the sleeve 11 side or to the inner wall of the developer passage hole 17a. The probability increases, and the developer passage hole 17a is more likely to be closed.

As described above, one of the factors that cause the blockage of the developer passage hole 17a is the presence of the toner group.

Therefore, by spraying the toner group before supplying it to the developer passage hole 17a, accumulation of the developer near the developer passage hole 17a is prevented, and the developer passage hole 17a It is conceivable to prevent occlusion.

However, in order to atomize the toner group as described above, it is necessary to perform a process such as uniformizing the toner and further uniforming the charging state, and the cost is increased to realize the above. There is an inconvenience.

On the other hand, if the toner is made uniform and its charge state is made uniform, the fluidity of the toner may be impaired and an image may be difficult to be formed. In this case, the purpose of preventing the developer passage hole from being blocked and realizing stable image formation cannot be achieved.

Therefore, the present inventors have completed the present invention by paying attention to the fact that the toner itself is prevented from being deposited near the developer passage hole.

Specifically, the first invention has a developer carrying means for carrying and transporting a charged developer, and a developer passage hole array in which a plurality of developer passage holes through which the developer passes are arranged. A developer passage control unit that controls passage of the developer supplied from the developer carrying unit through the developer passage hole according to an image signal from the outside; and the developer that has passed through the developer passage hole adheres. It is intended to be provided with an image receiving means. The developer passage control means includes a passage member having the developer passage hole formed thereon, and a rod-shaped vibrating body that vibrates the passage member is provided on the passage member along the developer passage hole row. It is a specific matter to arrange and arrange a vibrator on the vibrating body. In this case, the vibration by the vibrator is transmitted to the passing member via the vibrator. That is, the vibrating body serves as a vibration source to vibrate the passing member. For this reason, even if the developer attempts to accumulate near the developer passage hole, the vibration causes the developer to adhere to the passage member, that is, both are bonded at the interface between the developer and the passage member. Is prevented. Further, even if the developer adheres to the developer passage control means, it becomes possible to disconnect the two by vibration. For this reason, the accumulation of the developer is effectively prevented, and as a result, the developer passage hole is prevented from being blocked, and stable image formation is realized. Moreover, the vibrating body is
Since it is arranged along the developer passage hole array, it is possible to vibrate over the entire area of the developer passage hole array, and it is possible to effectively prevent the developer passage hole from being blocked. Become.

By causing such vibrations to act largely near the developer passage hole, the accumulation of the developer is further prevented. The following invention has been made based on such a viewpoint.

That is, the rod-shaped vibrator may be disposed on both sides of the developer passage hole row. Further, one end of the rod-shaped vibrator may be connected to each other to form a U-shaped vibrator, or both ends of the rod-shaped vibrator may be connected to each other to form an annular vibrator. Good. In this case, the vibrations from both sides of the developer passage hole row are transmitted to the developer passage hole row, and the vicinity of the developer passage hole row vibrates greatly. As a result, the accumulation of the developer is more reliably prevented.

When the vibrating body is formed in a rod shape or a U-shape, vibrators may be provided at both ends of the vibrating body. In this case, the vibrations of the vibrators at both ends of the vibrating body propagate through the vibrating body, and the vibrating body largely vibrates. For this reason, the passage member is further vibrated, and the accumulation of the developer is more effectively prevented.

On the other hand, when the vibrating body is formed in a ring shape,
Vibrators may be provided at a plurality of locations on the vibrator, respectively. Also in this case, the vibrating body vibrates greatly,
The passing member is further vibrated, and the accumulation of the developer is more effectively prevented.

Further, when a standing wave is generated in the vibrator, the node does not vibrate, so that the developer may be deposited at the position of the node on the passing member. From this viewpoint, when a plurality of vibrators are provided for the vibrator as described above, each vibrator may be configured so that the phases of the vibrations thereof are different from each other. in this case,
It is possible to prevent a traveling wave from being generated in the vibrator and forming a node portion in the passing member. For this reason, the whole of the passage member is evenly vibrated, and the disadvantage that the developer is deposited on the nodes of the vibration mode is eliminated.

Further, the vibrator may be configured to always operate during the operation of the developer passage control means. In this case, during the operation of the developer passage control means, that is, while the developer is intermittently flying through the passage hole, the accumulation of the developer is prevented, so that the developer passage hole is prevented. Blockage is reliably prevented, and stable image formation is realized.

On the other hand, a detector may be provided for detecting blockage of the developer passage hole, and the vibrator may be configured to operate according to the detection result of the detector. Here, "detection means"
May be configured to directly detect the blockage of the developer passage hole, or may be configured to perform a test print and detect whether an image is normally formed. . More specifically, for example, the detecting means includes a light emitting means for emitting light toward the image receiving means, and a light receiving means for receiving light reflected by the light emitted from the light emitting means and returning to the image receiving means. Then, it may be determined whether or not the image has been formed normally based on the presence or absence of the reflected light.

The detection means may detect the blocking of the passage hole, for example, when the passage hole has not been used for a long time. When the detecting means detects that the passage hole is closed, the vibrator is vibrated more than usual so that the developer closing the passage hole is reliably removed from the passage member. You may comprise.

The second invention has a developer carrying means for carrying and transporting a charged developer, and a developer passage hole array in which a plurality of developer passage holes for passing the developer are arranged.
A developer passage control unit that controls passage of the developer supplied from the developer carrying unit through the developer passage hole according to an image signal from the outside; and the developer that has passed through the developer passage hole adheres. It is intended to be provided with an image receiving means. The developer passage control means includes a passage member having the developer passage hole. One end of the passage member is fixed to the passage member, and the other end of the passage member is configured to be swingable. It is a specific matter that a vibrating body to be vibrated is disposed on the passing member, and a vibrator is disposed on the vibrating body. In this case, when the vibrator vibrates, the other end of the vibrating body bends, and the other end hits the passing member. For this reason, the passing member vibrates, and the accumulation of the developer is prevented. As a result, blockage of the developer passage hole is prevented, and stable image formation is realized.

The vibrator is formed in a flat plate shape extending along the developer passage hole array, and the end of the vibrator on the side remote from the developer passage hole array is fixed to the passage member. In this case, a plurality of vibrators may be arranged along the developer passage hole row. Also, unlike this, the vibrator is formed in a comb shape extending along the developer passage hole row, and the end of each comb tooth of the comb-shaped vibrator on the side remote from the developer passage hole row. The portion may be fixed to the passage member, and the vibrator may be disposed on each of the comb teeth. In this case, when the vibrator arranged along the developer passage hole row vibrates, the entire area of the developer passage hole row vibrates via the vibrator. Therefore, it is possible to effectively vibrate the whole area around the developer passage hole.

Further, the vibrator may be arranged on each side of the developer passage hole row. In this case, the vibration is transmitted to the row of developer passage holes from both sides thereof, and the vibration near the developer passage hole can be relatively increased. As a result, the accumulation of the developer near the developer passage hole is effectively prevented.

In the case where vibrators are provided on both sides of the developer passage hole array, vibrators provided on the vibrators on both sides are both disposed at an equal pitch, and one side is provided. The vibrator disposed on the vibrator of the above may be disposed with a half pitch shift from the vibrator disposed on the vibrator on the other side. In this case, for example, when the vibrators on both vibrators are arranged at equal pitches and are arranged so as to face each other, a region that is not sandwiched by the vibrators may occur in the developer passage hole row. In this region, the vibration is relatively small. Therefore, by disposing the vibrator on one vibrator at a half pitch from the vibrator on the other vibrator, the entire area of the developer passage hole array can be vibrated in the same manner. Thus, the accumulation of the developer is prevented over the entire area of the developer passage hole array.

The vibrator may be configured to vibrate by applying a voltage, and the phases of the voltages applied to the vibrators on the vibrators on each side may be the same. Alternatively, the phases of the voltages applied to the vibrators on the vibrating body on each side may be shifted from each other. When the phases of the voltages applied to the vibrators on the vibrators on the respective sides are the same, the vibrations from the respective sides are combined, and the vicinity of the developer passage hole array can be vibrated more greatly. . On the other hand, if the phases of the voltages applied to the vibrators on the vibrators on each side are shifted from each other, it becomes possible to vibrate the entire area near the developer passage hole array uniformly, and in any case, It is possible to effectively prevent the developer from being deposited.

In a vibration system constituted by vibrators, vibrators, and passing members on both sides, for example, when a node is formed at the position of the developer passing hole, the vibration near the developer passing hole is small. Therefore, the developer cannot be sufficiently prevented from being deposited. For this reason,
It is preferable that the vibration system is configured so as not to be a node at the position of the developer passage hole. In particular, if the vibration system is configured to be in the primary or tertiary vibration mode, the position of the developer passage hole becomes an antinode of the vibration, and the vicinity of the developer passage hole can be largely vibrated. For this reason, it is possible to effectively prevent the developer from being deposited near this.

Since such a passing member needs to be formed of an insulating material, it is formed of, for example, a polyimide resin. In this case, since the passing member has viscoelasticity, even if a vibrator made of a piezoelectric element such as PZT is directly disposed on the passing member, the vibration of the vibrator is transmitted to the developer passage hole array. It will be absorbed before you do it. However, by disposing a vibrator on the passage member and disposing a vibrator on the vibrator as in the first or second invention, the vibration of the vibrator is not absorbed on the way. It is possible to transmit to the developer passage hole row position. In this case, if tension is applied to the passage member, the vibration is more effectively transmitted to the developer passage hole array. As described above, the first or second invention is particularly preferably used when the passing member has viscoelasticity.

On the other hand, the third invention comprises a developer carrying means for carrying and transporting a charged developer, and a developer passage hole array in which a plurality of developer passage holes for passing the developer are arranged. A developer passing control means for controlling the passage of the developer supplied from the developer carrying means in accordance with the image signal of the above, and an image receiving means to which the developer passing through the developer passing hole array adheres. Target. The developer passage control means includes a passage member having the developer passage hole formed therein, and the passage member has a rigidity capable of transmitting vibration, and a vibrator is disposed on the passage member. Is a specific matter. In this case, when the vibrator vibrates, the passing member transmits the vibration to the vicinity of the developer passage hole array, and it is possible to prevent the developer from being deposited near the developer passage hole array. in this way,
In the case of the third aspect, unlike the first and second aspects, no vibrating body is provided, so that the number of parts is reduced and the manufacturing cost is reduced. At the same time, the apparatus itself is simplified, and the apparatus is made compact.

The passing member as described above only needs to have a rigidity and an insulating property at least capable of transmitting the vibration from the vibrator to the developer passage hole. What is necessary is just to comprise by the laminated structure of the ceramic which has.

In the third aspect, the passage member and the vibrator may be formed integrally. In this case, the manufacture is further facilitated, and the cost is reduced.

[0034]

As described above, according to the image forming apparatus of the first aspect of the present invention, the developer is prevented from being deposited near the developer passage hole, and the developer passage hole is closed. Can be prevented.

According to the invention of claims 2 to 7,
The vicinity of the developer passage hole can be effectively vibrated, and the adhesion of the developer can be more reliably prevented.

According to the eighth or ninth aspect of the present invention, the developer passage hole can be prevented from being blocked by the developer, and stable image formation can be realized.

According to the tenth aspect of the present invention, it is possible to prevent the developer from being deposited near the developer passage hole and to prevent the developer passage hole from being blocked.

According to the present invention, it is possible to reliably and effectively vibrate the vicinity of the developer passage hole, and to prevent the developer from being deposited near the developer passage hole. This can more reliably prevent the developer passage hole from being blocked.

According to the nineteenth or twentieth aspect of the present invention, it is possible to prevent the developer passage from being blocked by the developer, to reduce the manufacturing cost, and to reduce the size of the apparatus. .

[0040]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 shows an image forming apparatus according to a first embodiment of the present invention. An intermediate image holding belt 3 as an image receiving means, a transferring means 3 for transferring an image formed on the intermediate image holding belt 2 to a recording paper 5, and a fixing means 4 for fixing the image transferred on the recording paper to the recording paper 5. It is a fixing means for causing the fixing. Then, four heads 1 are provided, and each head 1 has:
Each toner as yellow, magenta, cyan, and black developers is stored respectively,
The image forming apparatus is configured to form a color image.

The toner has an average diameter of about 10 μm, and such a diameter can be measured by a small hole passage method (Multisizer manufactured by Coulter Inc.).

The intermediate image holding belt 2 is of an endless type, and includes a belt driving roller 21 for driving the intermediate image holding belt 2 and a ground roller 22. A back electrode 23 is provided on the back of the intermediate image holding belt 2.
And its power supply 24. Back electrode 23
Are arranged at positions facing each of the heads 1. Further, a belt cleaning 25 is disposed on the intermediate image holding belt 2 at a position facing the belt driving roller 21, and the belt cleaning 25 is pressed against the intermediate image holding belt 2. The toner or dirt forming an image on the image holding belt 2 is removed.

As such an intermediate image holding belt 2,
For example, a material obtained by dispersing conductive carbon in a polycarbonate having a thickness of about 150 μm may be used.
It may be set to about 340 mm for A4 paper. The belt drive roller 21 and the ground roller 22 include:
Both may have a diameter of about 25 to 30 mm. Further, as the back electrode 23, a metal plate or a film in which a conductive filler is dispersed in a resin may be used.
The voltage may be set to about 000 V, for example, it may be set to 1000 V.

The transfer means 3 includes a transfer roller 31 disposed opposite to the ground roller 22, and the transfer roller 31 is configured to be able to freely contact and separate from the ground roller 22. The transfer roller 31 is provided with a transfer power source 32. An electric field is generated by applying a voltage to the transfer roller 31 so that the toner on the intermediate image holding belt 2 is attracted to the recording paper 5 side. ing. Then, the transfer means 3 moves the intermediate image holding belt 2 and the recording paper 5 between the transfer roller 31 and the ground roller 22.
The image on the intermediate image holding belt 2 is transferred to the recording paper 5 by bringing the recording paper 5 into close contact.

As the transfer roller 31, for example, a roller having an outer diameter of about 20 mm by winding a urethane sponge around a shaft core having a diameter of 8 mm is used, and its resistance value is about 10 ⁷ Ω when 500 V is applied. What is necessary is just to become.

The fixing means 4 comprises a fixing roller 41 and a pressure roller 42 arranged opposite to each other.
A heat source 41a is disposed inside the fixing roller 41, and the heat generated by the heat source 41a causes the fixing roller 41a to emit heat.
Is in a high temperature state. Then, the fixing unit 4 transfers the heat generated by the fixing roller 41 and the pressure generated by the pressure between the pressure roller 42 and the fixing roller 41 to the recording paper 5.
, The toner is melted and fixed on the recording paper 5.

As shown in FIG. 2, the head 1 includes a sleeve 11, a toner regulating blade 12 disposed in contact with the sleeve 11, and the sleeve 11.
A toner supply roller 13 disposed opposite to the toner supply roller,
A hopper 14 that is provided on the side of the sleeve 11 and stores the toner, and a stirring unit 15 that is provided in the hopper 14 and stirs the toner are provided in a frame 16.

The sleeve 11 is formed in a cylindrical shape, and is configured to convey the toner by rotating counterclockwise while carrying the toner (see the arrow in the figure). Although the sleeve 11 is grounded (see FIG. 1), a DC or AC voltage may be applied to the sleeve 11.

The sleeve 11 is made of, for example, a metal such as aluminum or iron, an alloy, or rubber, and has an outer diameter of 16 to 20 mm and a thickness of 1 mm.
What is necessary is just to form it. The rotation speed of the sleeve 11 may be set to, for example, 20 to 400 mm / sec.

The toner regulating blade 12 forms a toner layer on the sleeve 11 and charges the toner by friction. The toner regulating blade 12 is provided so as to abut against the rotation direction of the sleeve 11 in the counter direction. ing. The toner is negatively charged by the toner regulating blade 12, and the toner layer formed on the sleeve 11 is set to be one layer. As such a toner regulating blade 12,
For example, it may be configured by attaching an elastic member such as a urethane rubber sheet to a phosphor bronze plate material.

The supply roller 13 supplies the toner to the sleeve 11 and is disposed so as to be in contact with the sleeve 11. The supply roller 13 is configured to rotate in the opposite direction with respect to the sleeve 11, and the amount of bite of the supply roller 13 into the sleeve 11 is, for example, 0.1 to 0.2 mm.
It is preferable to set the degree. As such a supply roller 13, for example, a roller obtained by winding a synthetic rubber such as a urethane sponge around a metal shaft core may be used, and its outer diameter may be formed, for example, to about 12 mm.

Then, the toner in the hopper 14 is agitated by the agitating means 15 and thereafter, the supply roller 1
The rotation of the sleeve 3 and the sleeve 11 causes the sleeve 3 to be carried on the surface of the sleeve 11. The toner regulating blade 12 removes excess toner from the carried toner, while the sleeve 11
The toner carried on the substrate is negatively charged.

The head 1 has a frame 16
A flexible print circuit (hereinafter referred to as an FPC) as a passage member constituting a developer passage control means opposed to the sleeve 11 at an opening portion of the FPC.
) Is provided (see FIG. 3). The insulating member 17c of the FPC 17 has a developer passage hole 17a through which the toner passes. A control electrode 17b for generating an electric field for pulling the toner carried on the sleeve 11 is provided on the surface around the developer passage hole 17a and on the sleeve 11 side. To prevent the toner that has passed through the developer passage hole 17a from spreading and flying on the surface around the developer passage hole 17a and on the side opposite to the sleeve 11 (on the side of the intermediate image holding belt 2). The guard electrode 17d for generating the electric field is provided. The control electrode 17b and the guard electrode 17d are both made of resin 17e, 1
7f.

The FPC 17 may be formed of, for example, a polyimide resin as the insulating member 17c, and its thickness may be set to 10 to 70 μm. The diameter of the developer passage hole 17a is 50 μm.
The thickness may be set to 200 μm, for example, 130 μm. Further, the control electrode 17b and the guard electrode 1
7d are both set to a thickness of 10 μm, and the resin coating 17
e and 17f may be set to a thickness of 1 to 2 μm.

The FPC 17 has viscoelasticity because the insulating member 17c is made of a polyimide resin. Although not shown, the FPC 17 has one end fixed and the other end fixed. Are arranged, for example, by being pulled by a spring member. For this reason,
A tension acts on the FPC 17.

Further, the voltage applied to the control electrode 17b may be set to 300V or less, and the voltage applied to the guard electrode 17d may be set to, for example, -100V.

The developer passage holes 17a are arranged in a row in the FPC 17, as shown in FIG. 4, so that a developer passage hole array 17g is formed.

The vibrator 6 is disposed in parallel with the developer passage hole row 17g (see FIG. 3 or FIG. 4). The vibrating body 6 is formed in a rod shape, and the FPC 1
7 is adhered. Such bonding may be performed by, for example, thermocompression bonding. Further, vibrators 61, 61 are provided at both ends of the vibrator 6, respectively. As such a vibrator 61, a piezoelectric element such as PZT may be used.

Each vibrator 61 includes an amplifier (horn) 6
2 attached. The horn 62 is formed so that its cross-sectional area is continuously and smoothly reduced as it goes downward, and is configured to concentrate the vibration energy of the vibrator 61 and transmit it to the vibrating body 6. ing.

The vibrating member 6 may have any rigidity capable of transmitting the vibration without absorbing the vibration, and may be formed of, for example, metal. In particular,
For example, stainless steel may be used. The board width is 5
mm and the plate thickness may be set to about 0.2 mm. The horn 62 may have any rigidity capable of transmitting the vibration without absorbing the vibration, and may be formed of, for example, metal. Specifically, it is preferable to use, for example, stainless steel or aluminum because the molding is easy.

The phases of the voltages applied to the respective vibrators 61 are set to be different from each other. Further, the vibration frequency of the vibrator 61 may be a sine wave of 1 MHz or less, for example, 20 kHz. This is because, when the vibration frequency increases, the toner and the FPC 17 vibrate in the same manner, and the coupling between the toner and the FPC 17 at the interface between the toner and the FPC 17 cannot be cut off.
This is because it may not be possible to prevent the accumulation of the toner.

A light emitting device 71 and a light receiving device 72 are disposed adjacent to the head 1 as detecting means for detecting blockage of the developer passage hole 17a (see FIG. 1 or FIG. 5). The light emitting device 71 is configured to emit light toward the intermediate image holding belt 2, and the light receiving device 72 receives reflected light in which light emitted by the light emitting device 71 is reflected by the intermediate image holding belt 2 and returns. It is configured as follows. The detection of the blockage of the developer passage hole 17a by the light emitting device 71 and the light receiving device 72 is performed as follows.

That is, first, a test print for applying toner to the intermediate image holding belt 2 by applying a voltage to the control electrode 17b provided in the developer passage hole 17a is performed. Next, the light emitting device 71 emits light to the intermediate image holding belt 2, and the light receiving device 72 detects the presence or absence of the reflected light.
That is, it is detected whether or not the developer passage hole 17b is closed. And this light emitting device 71
The light receiver 72 is configured to operate when the image forming apparatus is not used for a long period of time or the like, and to detect the blockage of the developer passage hole 17b.

Next, the operation and effects of the first embodiment will be described while explaining image formation in the image forming apparatus.

First, when a predetermined voltage (for example, 200 V) is applied to the control electrode 17b by an image signal from the outside, an electric field is formed between the control electrode 17b and the sleeve 11, and the electric field forms the sleeve. 11 is pulled. Then, the toner pulled by the electric field passes through the developer passage hole 17 a of the FPC 17. The toner that has passed through the developer passage hole 17a is pulled toward the intermediate image holding belt 2 by an electric field formed by the back electrode 23, and the toner adheres to the intermediate image holding belt 2. On the other hand, when a voltage equal to or less than a predetermined value is applied to the control electrode 17b, an electrode is not formed between the control electrode 17b and the sleeve 11, so that the toner carried on the sleeve 11 is carried on the sleeve 11. Will remain. For this reason,
The toner does not adhere to the intermediate image holding belt 2. As described above, by controlling the voltage applied to the control electrode 17b provided in each developer passage hole 17a of each head 1, toner adheres to the intermediate image holding belt 2 to form an image. I have.

During the image formation, the FPC
Voltage is always applied to the vibrators 61 of the vibrating body 6 disposed in the vibrator 17.
The first vibration is transmitted to the FPC 17 via the vibrating body 6.

Since the FPC 17 is formed of a polyimide resin, it has viscoelasticity. Therefore, for example, even if the vibrator 61 is directly disposed on the FPC 17, the vibration of the vibrator 61 is absorbed before being transmitted to the developer passage hole array 17g. However, by disposing the vibrator 6 on the FPC 17 and disposing the vibrator 61 on the vibrator 6 as in the first embodiment,
The vibration of the vibrator 61 can be transmitted to the position of the developer passage hole row 17g without being absorbed on the way. In addition, since the tension acts on the FPC 17, the vibration can be more effectively transmitted to the developer passage hole row 17g. Further, since each vibrator 61 is attached to the horn 62, the vibration of the vibrator 61 can be amplified. In addition, since the phases of the voltages applied to the pair of vibrators 61, 61 are set to be different from each other,
The vibrating body 6 generates a traveling wave. For this reason, it is possible to prevent the formation of a node portion in the FPC 17. As a result, the whole of the FPC 17 is vibrated, so that the inconvenience that the toner accumulates on the nodes can be eliminated.

Since the vibrator 61 is configured to always operate during image formation, while the toner intermittently flies and passes through the developer passage hole 17a, the accumulation of the toner is performed. Can be reliably prevented. As a result, the closure of the developer passage hole 17a is reliably prevented, and stable image formation can be realized.

The image forming apparatus is configured to detect a blockage of the developer passage hole 17a by the light emitting device 71 and the light receiving device 72 when the image forming device has not been used for a long time. When the blockage of the developer passage hole 17a is detected by the
Is set so as to vibrate more than usual by increasing the voltage applied to the. For this reason, the toner closing the developer passage hole 17a is removed by the developer passage control means 17.
It can be reliably removed from above.
Therefore, stable image formation can always be realized.

The vibrators 6 may be disposed at both sides of the developer passage hole array 17g, for example. As shown in FIG. 6, bar-shaped vibrators are respectively disposed at both sides of the developer passage hole row 17g, and a U-shaped structure is configured to connect one ends of the pair of bar-shaped vibrators to each other. The vibrating body 6a may be used. In this case, the vibrators 61 may be disposed at both ends of the vibrating body 6a as shown in FIG. Further, as shown in FIG. 7, bar-shaped vibrators are respectively disposed at both sides of the developer passage hole row 17g, and a pair of bar-shaped vibrators are connected to each other in an annular shape. The vibrating body 6b may be used. In this case, the vibrators 61, 61 may be disposed at both ends of the vibrating body 6b as shown in FIG.

Further, as shown in FIG.
The vibrator 61 may be provided only at one end of the vibrator.
In this case, the other end may be fixed.

<Second Embodiment> FIG. 9 shows an FPC 17 of an image forming apparatus according to a second embodiment of the present invention, which differs from the first embodiment in that a number of vibrators 63,
63 are provided, and the vibrations of the respective vibrators 63 are transmitted to the FPC 17.

9 to 11, reference numerals 8 and 8 denote the developer passage rows 1 at both sides of the developer passage hole row 17g.
Vibrators arranged apart from each other along 7 g.
In FIG. 9, the illustration of the vibrating body on one side of the developer passage hole row is omitted.

Each of the vibrators 8 is provided with the developer passage hole row 1.
7g, and each comb tooth 8a
The end on the side remote from the developer passage hole row 17g is FP
C17 is bonded to the fixed portion adhered to,
Each of the comb teeth 8a has a cantilever structure (see FIG. 9 or FIG. 11).

As shown in FIG. 10, the comb teeth 8a of the vibrating members 8 on each side are arranged at the same pitch, and
It is arranged to be shifted by a half pitch with respect to the other side of the comb teeth 8a. A vibrator 63 is provided on each comb tooth 8a, and the phases of the voltages applied to the vibrators 63 on the vibrators 8 on each side are shifted from each other. .

As shown in FIG. 11, the vibration system formed between the vibrators 8 on each side is configured to be in a primary or tertiary vibration mode (one point in FIG. 11). See dashed line).

Since the other components of the image forming apparatus are the same as those of the first embodiment, the same members are denoted by the same reference numerals, and description thereof will be omitted.

In the case of the second embodiment, a voltage is applied to each of the vibrators 63, and the vibrators 63 vibrate so that each of the comb teeth 8a having a cantilever structure is bent. The free end hits the FPC 17. For this reason, the FPC 17 vibrates, and the accumulation of toner can be prevented. As a result, it is possible to prevent the developer passage hole 17a from being closed, and to realize stable image formation.

Moreover, since the comb teeth 8a, 8a,... Are arranged along the developer passage hole array 17g, they can be vibrated over the entire area of the developer passage hole array 17g. Therefore, the vicinity of the developer passage hole 17a can be effectively vibrated.

Further, since the pair of vibrators 8, 8 are disposed on both sides of the developer passage hole row 17g with the developer passage hole row 17g interposed therebetween, the developer passage hole row 17g is located on both sides of the developer passage hole row 17g. Since the vibration is transmitted from the position, the vibration near the developer passage hole 17a can be relatively increased. As a result, it is possible to effectively prevent toner from being deposited near the developer passage hole 17a.

For example, when the vibrators 63, 63,... On the vibrating bodies 8, 8 on each side are arranged at the same pitch and are arranged so as to be opposed to each other, A region that is not sandwiched between the pair of vibrators 63, 63 is generated in the agent passage hole row 17g, and there is a possibility that the vibration may be relatively small in this region. However,
As in the second embodiment, the vibrators 63, 63,... On each vibrating body 8, 8 are arranged at the same pitch, and the vibrating body 63 on one vibrating body 8 is By displacing the vibrator 63 on the vibrator 8 on the side by a half pitch,
The entire area of the developer passage hole array 17g can be similarly vibrated, and the accumulation of toner can be prevented over the entire area of the developer passage hole array 17g.

The vibrators 6 on the vibrators 8 on each side
Since the phases of the voltages applied to 3, 63,... Are shifted from each other, the entire area near the developer passage hole array 17g can be uniformly vibrated, and the accumulation of toner can be effectively prevented. Will be able to

In a vibration system formed between the pair of vibrators 8 and 8, for example, when a node is formed at the position of the developer passage hole 17a, the vibration near the developer passage hole 17a is small. Therefore, the accumulation of toner cannot be sufficiently prevented. However, since the vibration system is configured to be in the primary or tertiary vibration mode, the position of the developer passage hole row 17g becomes an antinode of vibration, and the amplitude near the developer passage hole row 17g increases. Will be able to Therefore, it is possible to effectively prevent the toner from adhering to the vicinity. In order to set the vibration mode of the vibration system to the first or third order, for example, the vibration frequency of the vibrator 63 is changed, the length, width, thickness, or material of the vibrator 8 is changed. The thickness, width, or material may be changed, or the arrangement position of the vibrating body 8 may be changed.

As shown in FIG. 12, for example, as shown in FIG. 12, a plate-shaped vibrator 8b extending along the developer passage hole array 17g is used.
.. May be arranged on the vibrating body 8b. The vibrating body 8b may be provided only at one side of the developer passage hole row 17g, or may be provided at both sides thereof.

As shown in FIG. 11, the vibrating body 8 has a fixed portion and a comb tooth 8a formed so that each comb tooth 8a protrudes from a fixed portion bonded to the FPC. However, the present invention is not limited to this. For example, FIG.
As shown in FIG. 7, a fixing member 8d, which is a member separate from the comb teeth 8e, may be placed on the comb teeth 8e to fix the base ends of the comb teeth 8e.

Further, the vibrator 6 on the pair of vibrators 8
, 63,... May be configured to have the same phase. In this case, the vibrations from each side are combined, and the vicinity of the developer passage hole row 17g can be vibrated greatly.

<Third Embodiment> FIG. 14 shows a developer passage control means 9 of an image forming apparatus according to a third embodiment of the present invention, which is different from the first and second embodiments. The passage member 9 is configured to have rigidity capable of transmitting vibration.

The passing member 9 has a three-layer structure.
From the sleeve 11 side, the first layer 91 and the second layer 92 are each an insulating layer, and the third layer 93 is a vibration transmitting layer for transmitting vibration. A conductive layer 94 is formed so as to be sandwiched between the first layer 91 and the second layer 92.
It is arranged around the developer passage hole 9a. When a voltage is applied to the conductive layer 94, an electric field that pulls the toner carried on the sleeve 11 is generated.

The passing member 9 has a vibrator 64
Is to be placed.

The other components of the image forming apparatus are the same as those of the first embodiment. Therefore, the same members are denoted by the same reference numerals and description thereof will be omitted.

In the case of the third embodiment, the vibration of the vibrator 64 is transmitted by the vibration transmitting layer 93 of the passage member 9, and the vicinity of the developer passage hole 9a can be vibrated. Therefore, it is possible to effectively prevent the toner from being deposited near the developer passage hole 9a. As described above, by disposing the vibrator 64 directly on the passage member 9 without providing the vibrator, the number of components can be reduced, and the manufacturing cost can be reduced. The simplification of the device itself makes it possible to reduce the size of the device.

The passing member 9 as described above includes
What is necessary is just to form with the thing which has the rigidity which can transmit the vibration by the vibrator 64 to 17 g of developer passage holes. Specifically, for example, the ceramic formed by laminating and hardening this green sheet is used. What is necessary is just to use it.

Further, the passage member 9 and the vibrator 64 may be formed integrally. In this case, the manufacture is further facilitated, and the cost can be reduced.

<Other Embodiments> The present invention relates to the first embodiment.
The present invention is not limited to the third embodiment, but includes various other embodiments. That is, the first
In the third to third embodiments, the intermediate image holding belt 2 is used as the image receiving unit. However, the present invention is not limited to this. For example, the toner may be directly attached to recording paper or the like.

In the first to third embodiments, the head 1
Are provided so as to form a color image, but the invention is not limited to this. For example, only one head storing black toner is provided to form a black-and-white image. You may.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an image forming apparatus.

FIG. 2 is a schematic diagram showing a head.

FIG. 3 is an explanatory sectional view showing a developer passage hole portion of a head.

FIG. 4 is an explanatory perspective view showing an FPC in which the vibrating body and the vibrator according to the first embodiment are provided.

FIG. 5 is a schematic explanatory view showing a light emitting device and a light receiving device.

FIG. 6 is a view corresponding to FIG. 4, showing an FPC in which a vibrating body and a vibrator in a form different from FIG. 4 are provided.

7 is a diagram corresponding to FIG. 4 showing an FPC in which a vibrating body and a vibrator in a form different from FIG. 4 or FIG. 6 are provided.

FIG. 8 is a diagram corresponding to FIG. 4 showing an FPC in which a vibrating body and a vibrator in a form different from those of FIGS.

FIG. 9 is a perspective explanatory view showing an FPC in which a vibrator and a vibrator according to a second embodiment are provided.

FIG. 10 is an explanatory plan view showing an FPC in which a vibrator and a vibrator according to a second embodiment are provided.

FIG. 11 is an explanatory sectional view showing an AA section in FIG. 10;

FIG. 12 is a view corresponding to FIG. 9 showing an FPC provided with a vibrating body and a vibrator in a form different from that of FIG. 9;

FIG. 13 is an explanatory sectional view showing an FPC in which a vibrating body having a different form from that of FIG. 10 is provided.

FIG. 14 is an explanatory sectional view showing a head portion of an image forming apparatus according to a third embodiment.

FIG. 15 is an explanatory sectional view showing an image forming state in a conventional image forming apparatus.

FIG. 16 is an explanatory sectional view showing a state in which a developer passage hole is closed in a conventional image forming apparatus.

[Description of Signs] 1 Sleeve (developer carrying means) 2 Intermediate image holding belt (image receiving means) 9 Passing member 17 FPC (passing member) 6, 6a, 6b, 8, 8b, 8c Vibrating body 61, 63, 64 Vibration Child 71 Light-emitting device (detection means) 72 Light-receiving device (detection means) 9a, 17a Developer passage 17g Developer passage hole array

 ────────────────────────────────────────────────── ─── Continuing from the front page (71) Applicant 597063831 Owneds Brygga 13 421 57 Vestro Fround a Sweden (72) Inventor Masaichiro Tachikawa 1006 Ojidoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Masahiko Hashimoto, Inventor Matsushita Giken Co., Ltd. DB04 DB07 2H077 AD01 CA01 CA05 GA04

Claims (20)

[Claims] A developer carrying means for carrying and transporting a charged developer, and a developer passage hole array in which a plurality of developer passage holes through which the developer passes are provided, in response to an external image signal. A developer passage control unit that controls passage of the developer supplied from the developer carrying unit through the developer passage hole; and an image receiving unit to which the developer that has passed through the developer passage hole adheres. The developer passage control means has a passage member in which the developer passage hole is formed, and a rod-shaped vibrator that vibrates the passage member is disposed on the passage member along the developer passage hole row. An image forming apparatus, wherein a vibrator is provided on a vibrating body. 2. The image forming apparatus according to claim 1, wherein the vibrating member is disposed on both sides of the developer passage hole row. 3. The image forming apparatus according to claim 2, wherein the vibrating body is formed in a U-shape by connecting one ends of both rod-shaped vibrating bodies to each other. 4. The image forming apparatus according to claim 2, wherein both ends of the rod-shaped vibrating body on both sides are connected to each other to form a ring. 5. The image forming apparatus according to claim 1, wherein the vibrators are provided at both ends of the vibrator, respectively. 6. The image forming apparatus according to claim 4, wherein the vibrators are provided at a plurality of positions on the vibrator, respectively. 7. The image forming apparatus according to claim 5, wherein the vibrators are configured to have different phases of vibration. 8. The image forming apparatus according to claim 1, wherein the vibrator is always operated while the developer passage control means is operating. 9. An image according to claim 1, further comprising a detecting unit for detecting blockage of the developer passage hole, wherein the vibrator is configured to operate in accordance with a detection result of the detecting unit. Forming equipment. 10. A developer carrying means for carrying and transporting a charged developer, and a developer passage hole array in which a plurality of developer passage holes for passing the developer are arranged, and in response to an external image signal. A developer passing control means for controlling the passage of the developer supplied from the developer carrying means through the developer passing hole, and an image receiving means to which the developer passing through the developer passing hole adheres, The developer passage control means has a passage member in which the developer passage hole is formed. One end of the passage member is fixed to the passage member, and the other end is configured to be swingable, and a vibrating body that vibrates the passage member. But,
An image forming apparatus, wherein the image forming apparatus is provided on the passing member, and a vibrator is provided on the vibrating body. 11. The vibrating body according to claim 10, wherein the vibrating body is formed in a flat plate shape extending along the developer passage hole array, and an end of the vibrator on a side away from the developer passage hole array is a passage member. And a plurality of vibrators are arranged along the developer passage hole row. 12. The vibrating body according to claim 10, wherein the vibrating body is formed in a comb shape extending along the developer passing hole row, and each comb tooth of the comb-shaped vibrating body is separated from the developer passing hole row. An image forming apparatus, wherein an end on the side is fixed to a passing member, and a vibrator is disposed on each of the comb teeth. 13. The image forming apparatus according to claim 11, wherein the vibrating member is disposed on both sides of the developer passage hole row with the developer passage hole row therebetween. . 14. The vibrator according to claim 13, wherein the vibrators disposed on both vibrators on both sides are disposed at an equal pitch, and the vibrator disposed on one vibrator is connected to the vibrator on the other side. An image forming apparatus, wherein the image forming apparatus is disposed so as to be shifted by a half pitch with respect to a vibrator disposed on a vibrating body. 15. The structure according to claim 13, wherein each of the vibrators is configured to vibrate by applying a voltage, and the phases of the voltages applied to the vibrators on the vibrating body on each side are the same. An image forming apparatus, comprising: 16. The vibrator according to claim 13, wherein each vibrator is configured to vibrate by applying a voltage, and the phases of the voltages applied to the vibrators on the vibrating body on each side are shifted from each other. An image forming apparatus. 17. The method according to claim 13, wherein the vibrating system including the vibrating body, the vibrator, and the passing member on both sides is configured not to be a node at the position of the developer passing hole. Image forming device. 18. The image forming apparatus according to claim 17, wherein the vibration system is configured to be in a primary or tertiary vibration mode. 19. A developer carrying means for carrying and transporting a charged developer, and a developer passage hole array in which a plurality of developer passage holes for passing the developer are arranged, and in accordance with an external image signal. Developer passage control means for controlling passage of the developer supplied from the developer carrying means through the developer passage hole,
Image receiving means to which the developer that has passed through the developer passage hole array adheres, wherein the developer passage control means has a passage member in which the developer passage hole is formed, and the passage member is capable of transmitting vibration. An image forming apparatus having rigidity, wherein a vibrator is disposed on the passing member. 20. The image forming apparatus according to claim 19, wherein the passage member and the vibrator are formed integrally.