JPH08137282A - Developing device for wet type image forming device - Google Patents

Abstract

PURPOSE: To provide a developing device for a wet type image forming device, capable of preventing a latent image carrier from being damaged with foreign matter after entering into a developer supplying container. CONSTITUTION: The developing device for the wet type image forming device provided with the latent image carrier, a latent image forming device forming a latent image on the latent image carrier, a developer housing device having a fitting part 22 into which the developer supplying container 22' housing a developer used for replenishment is fitted and a developing device having a developer carrier which is disposed with a gap from the latent image carrier and whose surface has the supply of the developer from a developer housing part 21 by a developer supplying means is constituted to provide a filter member 23 in the fitting part 22 in the developer housing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device of a wet image forming apparatus such as a copying machine, a facsimile, a printer, etc., which carries out a wet development, and more specifically, a peripheral surface of a latent image bearing member is damaged by contamination of foreign matter. The present invention relates to a developing device of a wet type image forming apparatus which is never used.

[0002]

2. Description of the Related Art FIG. 4 is an enlarged view of the vicinity of a drum-shaped photosensitive member 1 which is a latent image carrier in an electrophotographic copying machine which performs wet development. As shown in FIG. 4, a conventional wet electrophotographic copying machine includes a photoconductor 1, a latent image forming apparatus 10 that forms a latent image on the photoconductor 1, and a replenishment developer (not shown). The developer accommodating device 20 having a mounting portion 22 into which the stored developer replenishing container 22 ′ is mounted, and the developer from the developer tank 21 disposed with a gap from the photoconductor 1 and by the developer supplying means. A developing device 30 having developing rollers 31 and 32 which are supplied developer carriers, a resist roller 51 for waiting a transfer sheet conveyed from a sheet feeding unit (not shown), and a transfer charger for transferring a toner image to the transfer sheet. 52 and a transfer device 50 having a separation roller 53 for separating the transfer paper after transfer from the photoconductor 1 and a turn belt 54, and a cleaning roller 41 for removing residual toner on the photoconductor 1 after transfer. Cleaning device 4
It has 0 and.

Further, the copying machine shown in FIG. 4 has an excessive developing solution removing member 33 for removing an excessive developing solution on the photoconductor 1 in the developing device 30, and this removing member 33. Are disposed with a gap from the photoconductor 1.

In this wet electrophotographic copying machine, a document on a contact glass (not shown) is illuminated by a scanning illumination device, and its reflected light is passed through a scanning mirror, a lens and a reflecting mirror (none of which is shown). Then, the corona discharger 2, which is a uniform charger, is already uniformly charged to, for example, the positive polarity, and the image is projected onto the photoconductor 1 from which the charges outside the image forming area have been removed by the erase 3. As a result, an electrostatic latent image is formed on the photoconductor 1.

In the developing device 30 provided on the right side of the photosensitive member 1, the electrostatic latent image is charged to, for example, a negative polarity by the two developing rollers 31 and 32 which are the developer carrying members. The developer containing toner is supplied to form a toner image, and the excess developer on the photoconductor 1 is transferred to the reverse roller 3
Remove in 3. Here, the developing rollers 31, 32
Holds a gap of, for example, 0.15 mm from the surface of the photoconductor, and also has a developing bias of, for example, 150 V as a developing bias for preventing background stain.
Is applied. Further, the developing rollers 31, 32 and the reverse roller 33 are provided with a scraper 31 for cleaning the surface.
a, 32a and 33a are in contact with each other. Of these, the scraper 31a that is in contact with the upstream first developing roller 31
On the surface of the developing roller 31, a developing solution reservoir is formed to collect the developing solution which is drawn from the developing solution tank 21 and discharged from the supply nozzle 34 in the developing solution container described later. The developer in the developer reservoir is pumped up by the first developing roller 31 and conveyed to the surface of the photoconductor 1. Then, the surface of the photoreceptor 1 and the first developing roller 31
A developer pool is also formed in the portion facing the surface to uniformly supply the developer in the width direction of the photoconductor 1.

On the peripheral surface of the photosensitive member 1 which has passed through the facing portion of the developing device 30, a transfer paper which is conveyed from the paper feeding portion and is made to stand by at the registration roller 51 is kept in timing by the roller 51 with respect to the leading edge of the toner image. Take and transport. Then, the transfer charger 52 applies an electric charge having a polarity opposite to that of the toner to the back surface of the transfer paper which is in close contact with the photoconductor 1 to transfer the toner image onto the transfer paper. The transfer paper on which the toner image has been transferred is separated by the separation roller 5
3 and the turn belt 54 separate from the photoconductor 1, and the paper is ejected as a copy paper to the outside of the machine through a fixing device (not shown). On the other hand, in the photoreceptor 1 after the transfer, the residual toner is removed by the cleaning roller 41 and the cleaning blade 42 of the cleaning device 40 provided on the left side thereof, and the residual charge is eliminated by the neutralization lamp 43. Prepare for the next uniform charging by the corona discharger 2.

This copying machine, as shown in FIG.
A developing solution tank 21 that contains a developing solution to be supplied to the developing device 30 and the cleaning device 40 is provided. On the top lid of this developer tank 21, Isopar (trade name)
A mounting portion 22 for mounting a developer replenishing container 22 'containing a developer such as, and a toner replenishing portion 24 for mounting a toner replenishing container 24' containing a high toner concentration developer.
Are provided.

Then, these supply containers 22 ', 24'
Upside down so that the exit of the
The well-known developer tank 21 mounted on the toner supply unit 24
Based on the internal liquid level control method and the high-concentration toner replenishment control method, the developer and the high-toner-concentration developer are stored in the developer tank 21.
Will be replenished inside. That is, when the developer supply container 22 ′ is mounted on the mounting portion 22, the nozzle 22 ′ a at the tip thereof is pushed up by the part 22 a of the mounting portion 22 as shown in FIG. The developer can be replenished from the gap formed in the vicinity of'a. Incidentally, FIG. 6 (a)
In the state shown in (1), the developer outlet of the developer supply container 22 'is in contact with the liquid surface in the developer tank 21, and air is not introduced from the outlet, so that the developer is not supplied.
When the height of the liquid surface in the developer tank 21 decreases from this state, air enters the container 22 'from the outlet, and at the same time, the developer is replenished from the container 22'.

When the toner replenishing container 24 'is attached to the toner replenishing section 24, as shown in FIG. 6 (b), when the toner concentration in the developer tank 21 decreases, the nozzle 24 at the tip of the toner replenishing container 24'. “A” is pushed up by the tip Q of the push-up arm Q connected to the plunger of the toner supply solenoid, and the developer can be replenished from the gap formed near the nozzle 24′a.

The replenished developer and high-toner-concentration developer are mixed and agitated by an agitating flow by a pump P shown in FIG. It is stored in the tank 21. This developing solution is supplied by the pump P as shown in FIGS.
Via the developer supply pipes 25 and 26 shown in FIG.
0, the cleaning device 40 is supplied to each of the cleaning devices 40, and after being used for development and removal of excess developer, the developing device 30,
It is circulated by being collected in the developer tank 21 via the developer collecting pipes 25 ′ and 26 ′ provided in each of the cleaning devices 40.

The developing solution tank 21 as described above is
As shown in FIG. 7, the developing device 30 and the cleaning device 40
The developer is collected from the developing device 30 so that the developer returns to the developer tank 21 by gravity even when the apparatus is powered off.

Further, the circulation of the developing solution is turned on / off in synchronization with the turning on / off of the main motor.
In the copying machine, the pump is activated after the print button is pressed. Also, the developer supply container 22 '
The toner tank 24 ′ and the toner supply container 24 ′ need to be replaced when they are empty. Therefore, the developer tank 21 is arranged at a position where they can be easily replaced, for example, on the front side of the image forming apparatus provided with an openable door. Has been done.

[0013]

By the way, in the copying machine as described above, since the developer replenishing container is conventionally disposable, no foreign matter such as sand or dust is mixed into the replenishing container. However, in recent years, the developer supply container has been recycled, and especially when the user re-bottoms the developer, foreign matter such as sand or dust may be mixed in the supply container. . Then, when the developer supply container is set on the upper lid of the developer tank while foreign matter is mixed, the foreign matter is mixed in the developer tank and the mixed foreign matter is conveyed to the developing unit together with the developer. There is a problem that it is caught between the photoconductor and the developing roller or the reverse roller, and the peripheral surface of the photoconductor is damaged.

The present invention has been made in view of the above problems, and it is an object of the present invention to develop a wet image forming apparatus in which the latent image carrier is not damaged by foreign matter mixed in the developer supply container. It is to provide a device.

[0015]

In order to achieve the above object, the invention of claim 1 provides a latent image carrier, a latent image forming device for forming a latent image on the latent image carrier, and replenishment. Developer accommodating device having a mounting portion to which a developer replenishing container accommodating a developer for toner is mounted; In a developing device of a wet image forming apparatus including a developing device having a developing solution carrier on the surface of which a developing solution is supplied, a filter member is provided in the mounting portion of the developing solution container. Is.

According to a second aspect of the present invention, in the developing device of the wet image forming apparatus according to the first aspect, a filter member having a pore size smaller than a gap between the latent image carrier and the developer carrier is used as the filter member. It is characterized by being used.

According to a third aspect of the present invention, in the developing device of the wet image forming apparatus according to the first or second aspect, the developing device is provided with an excessive developing solution removing member for removing an excessive developing solution on the latent image carrier. A filter member provided with a gap from the latent image bearing member and having a pore size smaller than the gap between the latent image bearing member and the excess developer removing member as the filter member. is there.

According to a fourth aspect of the present invention, in the developing device of the wet image forming apparatus according to the first, second or third aspect, the mounting portion of the developing solution accommodating device is configured such that the filter member can be attached and detached, and It is characterized in that a replenishment control mechanism for replenishing the developer to the developer containing section is provided only when the filter member is installed in the mounting section.

[0019]

According to the invention of claim 1, foreign matter such as sand and dust mixed in the developer supply container or adhering to a portion such as an inner wall of the developer supply container is the mounting portion in the developer accommodating device. Is collected by the above-mentioned filter member provided in the above before being supplied to the above-mentioned developing solution container.

According to the second aspect of the present invention, since the diameter of the filter member is smaller than the gap between the latent image carrier and the developer carrier, the foreign matter passing through the filter member is The size is smaller than the gap between the latent image carrier and the developer carrier. Therefore, the foreign matter circulates together with the developing solution between the developing device and the developing solution accommodating device without being caught between the latent image carrier and the developing solution carrier.

According to the third aspect of the present invention, since the diameter of the filter member is smaller than the gap between the latent image carrier and the developer removing member, the foreign matter passing through the filter member is The size is smaller than the gap between the latent image carrier and the developer removing member. for that reason,
The foreign matter circulates between the developing device and the developing solution accommodating device together with the developing solution without being caught between the latent image carrier and the excess developer removing member.

In the invention of claim 4, the developer is supplied to the developer containing portion through the filter member only when the filter member is provided in the mounting portion.

[0023]

EXAMPLE A first example in which the present invention is applied to a wet electrophotographic copying machine (hereinafter referred to as a copying machine) which is a wet image forming apparatus will be described below. Incidentally, the configuration not particularly described is the same as that of the conventional copying machine shown in FIG.
FIG. 1 is a sectional view showing a mounting portion of the copying machine of the first embodiment, and FIG. 2 is a perspective view showing a filter provided in the mounting portion.

The copying machine of this embodiment, as shown in FIG. 4, develops a photoreceptor 1 which is a latent image carrier, a latent image forming apparatus 10 for forming a latent image on the photoreceptor 1, and a developer. A developing solution accommodating device 20 having a mounting portion 22 for replenishing the developing solution tank 21 which is a solution accommodating section, and a developing device whose surface is a developing solution carrier to which the developing solution is supplied from the developing solution tank 21 The roller 31 and the reverse roller 33 which is a surplus developer removing member for removing surplus developer on the latent image carrier 1.
And a cleaning device 40 having a cleaning roller 41 which is a developer removing member for removing the developer on the photoconductor 1. These structures are similar to the above-mentioned conventional ones.

Next, the characteristic parts of the copying machine of this embodiment will be described. As shown in FIG. 1, the copying machine of this embodiment is provided with a filter 23 in the mounting portion 22 of the developer accommodating device 20, and the developer supply container 2
2'is attached to the attachment portion 22 via the filter 23. To further explain, the filter 23 is
The diameter is smaller than the gap between the photoconductor 1 and the developing roller 31, and the photoconductor 1 and the reverse roller 33 are provided.
It is set smaller than the gap between and. Therefore, even if foreign matter is not collected by the filter 23 and enters the developer tank 21, the size of the foreign matter is smaller than the gap between the photoconductor 1 and the developing roller 31. In addition, it is smaller than the gap between the photoconductor 1 and the reverse roller 33. In addition, the filter 2
3 has a collar portion 23a as shown in FIG. 2, and the collar portion 23a is supported by the mounting portion 22 and is detachably attached.

When the developer replenishing container 22 'is mounted on the mounting portion 22 to which the filter 23 is mounted, the nozzle 22'a at the tip of the replenishing container 22', as shown in FIG. Through the filter 23, the mounting portion 22
And is pushed up. When the developer is replenished as described above, the container 22 '
Foreign matter mixed in or adhering to a portion such as an inner wall thereof is collected by the filter 23. Further, even if foreign matter passes through the filter 23,
The foreign matter has a size of the photoconductor 1 and the developing roller 3
It is smaller than the gap between the photoconductor 1 and the reverse roller 33. Therefore, even if a developing solution containing a developer containing foreign matter is supplied to the photoconductor 1, the foreign matter may be present between the photoconductor 1 and the developing roller 31 or between the photoconductor 1 and the reverse roller 33. I can't stand in between. Therefore, the peripheral surface of the photoconductor 1 is not damaged by the foreign matter.

Next, a second embodiment in which the present invention is applied to a wet electrophotographic copying machine (hereinafter referred to as a copying machine) which is a wet image forming apparatus will be described. It should be noted that the present embodiment will be described only regarding differences in configuration from the above-described first embodiment.

In the copying machine of the present embodiment, the mounting portion 22 of the developer accommodating apparatus 20 is constructed so that the filter 23 can be attached and detached, and the developer can be provided only when the filter 23 is installed in the mounting portion 22. A replenishment control mechanism for replenishing the developer tank 21 is provided.

That is, the filter 23 has a collar portion 23a.
And a downward convex portion 23b as shown in FIG. 3 is provided on the surface of the collar portion 23a that is in contact with the mounting portion 22. Then, when the developing tank 21 is mounted on the mounting portion 22, the developing tank 21 is inserted through the hole 22b on the mounting portion 22.
The convex portion 23b projects into the inside.

Further, as shown in FIG. 3, the mounting portion 22 has a developer replenishment control member 27 in the vicinity thereof,
The control member 27 is provided with a shaft 28 in the developer tank 21.
It is attached rotatably around. Further, as shown in FIG. 3, a part of the control member 27 is partially attached to the shaft 2.
8 is extended to the opposite side of the contact portion 27a of the developer supply container 22 'with the tip portion 22'a, and the extended portion 27b has one end fixed to the mounting portion 22. The other end of 29 is attached.

The control member 27 is the filter 23.
When it is not attached to the mounting portion 22, the extension portion 27b thereof is biased by the spring 29 so as to be pulled upward, and is positioned as shown by the alternate long and short dash line in FIG. When the filter 23 is attached to the mounting portion 22, the convex portion 23b of the filter 23 pushes down the extension portion 27b. Then, along with this depression, the contact portion 27a
Rotates clockwise about the shaft 28 until it comes into contact with the filter 23, and at the contacted position, as shown in FIG. 3, the developer can be supplied to the developer tank 21.

In the copying machine of the present embodiment having the above-mentioned structure, when the filter 23 is attached to the mounting portion 22, the control member 27 pushes up the extension portion 27b by the convex portion 23b. Axis 28
3 to rotate to the position shown by the solid line in FIG. 3, and the developer can be supplied to the developer tank 21. Then, when the replenishment container 22 ′ is attached to the attachment portion 22 in this state, the nozzle 22′a at the tip of the replenishment container 22 ′ is pushed up by the abutting portion 27a, and the developer passes through the filter 23. Is replenished from the replenishing container 22 'to the developer tank 21. Also,
When the filter 23 is not attached to the mounting portion 22, the control member 27 is in the position shown by the alternate long and short dash line in FIG. 3, and even if the replenishment container 22 ′ is mounted in this state, Since the nozzle 22'a is not pushed up by the contact portion 27a, the developer containing the foreign matter is not replenished from the replenishment container 22 'to the developer tank 21. Therefore, the developer is replenished to the developer tank 21 only when the filter 23 is attached to the mounting portion 22, and the foreign matter in the developer is always removed by the filter 23 during the replenishment. Even if the developing solution in the developing solution tank 21 is circulated between the developing device 30 and the developing solution tank 21, the peripheral surface of the photoreceptor is not damaged.

[0033]

According to the first aspect of the present invention, foreign matter such as sand and dust mixed in the developer supply container or adhering to a portion such as the inner wall of the developer supply container is contained in the developer storage device. Since it is collected by the filter member provided in the mounting portion before being supplied to the developer storage portion, there is an excellent effect that the latent image carrier is not scratched by foreign matter.

Further, according to the second aspect of the invention, the foreign matter passing through the filter member and mixed in the developer containing portion has a size smaller than the diameter of the filter member. Even if the latent image bearing member is conveyed to the developing unit, it does not get caught between the latent image bearing member and the developing solution bearing member, so that there is an excellent effect that the latent image bearing member is not damaged.

Further, according to the third aspect of the invention, the foreign matter passing through the filter member and mixed in the developer containing portion has a size smaller than the diameter of the filter member. Even if the latent image carrier is conveyed to the developing unit, it does not get caught between the latent image carrier and the developer removing member, so that the latent image carrier is not damaged.

Further, in particular, according to the invention of claim 4, the developer is supplied to the developer accommodating portion through the filter member only when the filter member is installed in the mounting portion. , Even if the developer replenishing container is set to the mounting portion without attaching the filter member,
The developer containing the foreign matter is not supplied from the developer supply container. As a result, the latent image carrier is supplied with the developer containing the developer from which the foreign matter has been removed, and there is an excellent effect that the foreign matter does not scratch the latent image carrier. In addition, since the filter member provided in the mounting portion of the developer storage device is removable, there is an effect that the filter member can be easily cleaned.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mounting portion according to a first embodiment.

FIG. 2 is a perspective view showing a filter provided in the mounting portion.

FIG. 3 is a sectional view showing a mounting portion in the second embodiment.

FIG. 4 is an enlarged view showing the vicinity of a photoconductor in a conventional copying machine.

FIG. 5 is a perspective view showing the vicinity of a developer tank in the copying machine.

FIG. 6A is a sectional view showing a mounting portion of the copying machine. FIG. 3B is a sectional view showing a toner replenishing section in the copying machine.

FIG. 7 is a perspective view showing a circulation path of a developing solution in the copying machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 10 Latent image forming device 20 Developer solution accommodating device 21 Developer solution tank 22 Mounting part 22 'Developer replenishing container 23 Filter 27 Developer replenishment control member 29 Spring 30 Developing device 31 Developing roller 32 Developing roller 33 Reverse roller

Claims (4)

[Claims] 1. A development having a latent image carrier, a latent image forming device for forming a latent image on the latent image carrier, and a mounting portion to which a developer replenishing container containing a replenishing developer is mounted. A liquid storage device, and a developing device having a developer carrier which is disposed with a gap from the latent image carrier and has the developer supplied to the surface thereof from the developer container by the developer supply means. A developing device for a wet image forming apparatus, wherein a filter member is provided in the mounting portion of the developer containing device. 2. A developing device for a wet image forming apparatus according to claim 1, wherein the filter member is a filter member having a pore diameter smaller than a gap between the latent image carrier and the developer carrier. . 3. The developing device is provided with an excess developer removing member for removing an excess developer on the latent image bearing member with a gap from the latent image bearing member, and the filter member has a hole diameter. 3. The developing device for a wet image forming apparatus according to claim 1, wherein a filter member smaller than a gap between the latent image carrier and the excess developer removing member is used. 4. The developer is stored in the developing solution accommodating portion only when the mounting portion of the developing solution accommodating device is configured such that the filter member is detachable and the filter member is installed in the mounting portion. 4. The developing device for a wet image forming apparatus according to claim 1, further comprising a replenishment control mechanism that enables replenishment.