JPH05107991A - Image forming device - Google Patents

Abstract

PURPOSE:To coat the surface of a photosensitive drum with a liquid for removing a corona product from a liquid coating device, and to wipe water, without making the size of a photosensitive drum large. CONSTITUTION:A coating device 12 having a housing container 10 storing the water on the lower part of a transferring/carrying belt 4, and a cleaning blade 13 whose top end is abutted on the surface of the transferring/carrying belt 4, and a recovery container 14 are disposed. When the materials of the corona product, etc., stuck on the photosensitive drum 1 are removed, the surface of the transferring/carrying belt 4 is coated with the water by the coating roller 11, in a state where the photosensitive drum 1 is rotated in the direction of the arrow A. The surface of the photosensitive drum 1 is rubbed by the transferring/carrying belt 4 coated with the water, to remove the corona product. The surface of the transferring/carrying belt 4 is further, moved in the direction of the arrow D, and the water including the corona product is scratched by the cleaning blade 13, and recovered to the recovery container 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to image forming apparatuses such as copiers, facsimiles and printers. More specifically, the surface of an image carrier is moved endlessly while corona discharge is applied to the surface of the image carrier for charging and discharging. The present invention relates to the removal of corona products on the surface of an image carrier in an image forming apparatus repeatedly used for image formation.

[0002]

2. Description of the Related Art Conventionally, in this type of image device, a phenomenon called image deletion has occurred due to long-term use under high humidity. This image flow is caused by corona products such as various nitrogen compounds including electrolytes produced by corona discharge during charging, transfer, separation, charge removal, metal oxides, and other oxide compounds being an image carrier, for example, the surface of a photoreceptor. This is a phenomenon in which the corona product absorbs water and the resistance of the surface of the photoconductor is lowered, and the charge moves on the photoconductor, so that a clear image cannot be obtained.

Such image deletion has a high surface hardness,
A layer of amorphous silicon laminated on a conductive support, which has been attracting attention as an image bearing member in recent years due to its excellent wear resistance and heat resistance, and a layer of a high-hardness resin coating layer on the surface of a photosensitive layer. In particular, it is likely to occur. This is because the surface hardness of these image bearing members is relatively high, and a normal cleaning blade used for cleaning the surface of the image bearing member cannot scrape off corona products adhering to the surface. by.

As a conventional solution to the above-described image deletion, the image carrier is taken out of the apparatus and dehumidified by heating or washed with an aqueous solution when the image deletion occurs. According to this, it is necessary to take out the image carrier from the apparatus, which is troublesome and troublesome.

In order to save the trouble of taking out such an image bearing member from the apparatus, a liquid applying device for applying a liquid for removing ion products such as water and basic ion aqueous solution to the surface of the image bearing member is opposed to the surface. It has been proposed to dispose them (Japanese Patent Laid-Open No. 60-49352 and Japanese Patent Laid-Open No. 60-808).
90, JP-A-60-83067, JP-A-6
No. 1-6678).

However, according to this structure, since the liquid coating device is arranged directly opposite to the surface of the image bearing member, it is usually inside the moving path of the surface of the image bearing member (for example, inside the hollow of the photosensitive drum). Is a dead space that cannot be effectively used, but in order to secure a space for disposing the liquid coating device on the movement path of the image carrier surface, the movement path of the image carrier surface is lengthened, that is, the image carrier is It was necessary to increase the size. In particular, in the image forming apparatus which has been advanced in colorization in recent years, since a plurality of developing devices are arranged on the surface of the image carrier, almost no empty space remains on the moving path of the surface of the image carrier. However, the size of the image carrier is inevitable.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
An object of the present invention is to provide an image forming apparatus that can be provided with a liquid application device without increasing the size of the image carrier.

[0008]

In order to achieve the above-mentioned object, the invention of claim 1 is such that the surface of the image carrier is moved endlessly while corona discharge is applied to the surface of the image carrier for charging and discharging. In an image forming apparatus that repeatedly uses a transfer belt for image formation, a conveyor belt device that conveys a transfer material onto the surface of an image carrier, a cleaning unit that cleans the surface of the conveyor belt, and an image carrier of the conveyor belt device during non-image formation. The invention according to claim 2 is characterized in that a coating means for coating a liquid for removing corona products on the surface of the image carrier is provided on the surface of the conveyor belt which is in contact with or close to the surface of the body. In the image forming apparatus of item 1, there is provided drive means for driving the surface of the image carrier and the surface of the conveyor belt so as to have a relative speed at a contact portion during non-image formation. The invention of 3 is In the image forming apparatus according to claim 1, a driving unit that moves the conveyor belt in a direction opposite to that during image formation during non-image formation, and a removed material removed from the surface of the conveyor belt by the cleaning unit during image formation. And a recovery container for recovering the removed material removed from the surface of the conveyor belt by the cleaning means at the time of non-image formation.

[0009]

According to the present invention, the surface of the conveyor belt, which is in contact with or close to the surface of the image bearing member of the conveyor belt device, is formed during non-image formation.
A liquid for removing the corona product on the surface of the image carrier is applied by the application means, and thereby the liquid is applied to the surface of the image carrier via the surface of the conveyor belt.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a copying machine) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a copying machine according to this embodiment. The photosensitive drum 1, which is an image carrier, is rotationally driven in the direction of arrow A. The photoconductor drum 1 has a photosensitive layer formed on a drum-shaped conductive substrate. As the photosensitive layer, amorphous Si, Se, Te, AS ₂ Se ₃ ,
Alternatively, a known photoconductor such as an organic compound can be used. Further, a high hardness resin coat layer may be provided on the photosensitive layer. Around the photosensitive drum 1, a charging device, an exposing device, a developing device, a discharging device, a cleaning device, etc., which are not shown, are arranged in order to execute the electrophotographic process. Of these, the charging device and the static eliminator are equipped with a corona discharger. An insulating film (for example, a polyester film having a thickness of 125 μm) that is endlessly moved around the roller pairs 2 and 3 which are rotationally driven in the directions of arrows B and C, is formed below the photosensitive drum 1. A belt conveying device including a transfer / conveying belt 4 is provided. The surface of the transfer / conveyance belt 4 moves in the direction of arrow D, whereby the transfer paper 5 is conveyed from the left side to the right side in the drawing. A DC power supply 7a and an AC power supply 7b are used as power supplies so as to face the surface of the transfer / transport belt 4 wound around the roller 3 on the upstream side in the transfer paper transport direction.
The corona discharger 6 connected in series is provided. The roller 3 is formed of a conductive material so as to function as a counter electrode of the corona discharger 6, and is grounded. A grounded conductive roller 8 is provided so as to face the lower surface of the photosensitive drum 1 with the transfer / transport belt 4 interposed therebetween.

The above-mentioned configuration is, for example, Japanese Patent Publication No. 61-4099.
It is publicly known as disclosed in Japanese Patent Publication No. 0, and operates as follows. That is, the photosensitive drum 1 is rotated in the direction of arrow A, and a toner image is formed on the surface thereof by a well-known electrophotographic process. During this period, the surface of the transfer / conveyance belt 4 is charged by the corona discharger 6 to a polarity opposite to the charging polarity of the toner forming the toner image, and the transfer paper 5 sent from the paper feeding / conveying device (not shown) is transferred to the photosensitive drum. 1 The sheet is conveyed to a transfer position which is a contact portion with the surface. Then, the toner image that has moved to the transfer position due to the movement of the surface of the photosensitive drum 1 is transferred onto the transfer paper 5 on the transfer / transport belt 4 onto the transfer / transport belt 4
Transferred by Coulomb force due to surface charge. The transfer paper on which the toner image has been transferred is conveyed by the transfer / conveyance belt 4 as it is, separated from the transfer / conveyance belt 4 by a separating device (not shown), passed through a fixing device (not shown), and discharged outside the machine. .. On the other hand, the surface of the photosensitive drum 1 after the transfer is initialized by the cleaning device and the static eliminator and is prepared for the next copy.

According to the above-mentioned structure, since the photoconductor drum 1 is subjected to corona discharge by the charging device or the static eliminator, the corona product as described above may be attached to the surface of the photoconductor drum 1. Therefore, in this embodiment, a liquid for removing corona products, for example, water is applied to the surface of the photosensitive drum 1 by using the transfer / conveyance belt 4 to wipe the surface of the photosensitive drum 1 with water. For this reason, in the illustrated example, the storage container 10 in which water is stored facing the downward moving surface of the transfer / transport belt 4.
And a coating roller 11 part of which is submerged in the water in the storage container 10.
And a cleaning blade 13 having a tip abutting on the surface of the transfer / conveyance belt 4.
And a collecting container 14 for collecting and collecting the adhered matter scraped off from the surface of the transfer / transport belt 4 by the cleaning blade 13.
To arrange. The coating roller 11 is the swing arm 1.
5 is rotatably supported by the upper end portion of the motor 5, and is rotated by a drive source (not shown). In addition, the lower end portion of the swing arm 15 is provided with springs 15 from opposite directions.
One end of a and the plunger of the solenoid 15b are connected. The spring 15a swings the swing arm 15 in the direction in which the coating roller 11 retracts from the surface of the transfer / transport belt 4, and the solenoid 15b swings the swing arm 15 in the opposite direction. Is.

In the above-mentioned structure, when removing adhered substances such as corona products on the photosensitive drum 1, when the transfer paper 5 does not exist on the surface of the photosensitive drum 1, for example, during warm-up after turning on the mechanical power, etc. When the photoconductor drum 1 is rotating in the direction of arrow A at the time of starting the first time or other than the transfer process, the swing arm 15 is swung by driving the solenoid 15b. 11 is brought into contact with or close to the surface of the transfer / transport belt 4 and the storage container 1
The water pumped from within 0 is applied to the surface of the transfer / transport belt 4. When the transfer / conveyance belt 4 coated with water moves to a portion facing the surface of the photoconductor drum 1,
Rub the surface to remove deposits. And further arrow D
Moving in the direction, the cleaning blade 13 scrapes off and cleans the adhered matter from the photosensitive drum 1 that has adhered to the surface. The deposits scraped off by the cleaning blade 13 are collected in the collection container 14.

Here, in order to enhance the ability to remove the deposits from the surface of the photosensitive drum 1, the relative speed at the transfer position between the surface of the photosensitive drum 1 and the surface of the transfer / conveying belt 4 is different from the transfer step. May be made different. For this purpose, the rotation direction of the transfer / conveyance belt 4 may be the same as that in the transfer step, and the linear velocity thereof may be switched to a relatively low speed or a high speed as compared with the transfer step. The direction itself may be switched opposite to that in the transfer step. In this way, when the rotation direction of the transfer / conveyance belt 4 is to be reversed from that in the transfer step, the arrangement of the coating device 12 and the cleaning blades 13 and 14 is reversed from the example shown in the drawing, whereby In the same manner as in the above case, the surface of the transfer / conveyance belt 4 coated with water is cleaned by the cleaning blade 13 after facing the surface of the photosensitive drum 1. The rotation state of the transfer / conveyance belt 4 may be the same as that in the transfer step, and the linear velocity and the rotation direction of the photosensitive drum 1 may be switched.

In the above embodiment, since the toner adhering to the transfer belt is removed by the cleaning blade 13 during the image forming operation in which the transfer process is performed, this removal is performed in the recovery container 14. The toner and the water containing the corona product at the time of removing the corona product by applying the liquid are mixed. For this reason, in order to collect the removed toner as waste toner from the collection container 14, the water and the waste toner are in a mixed state, so that the collected material in the collection container 14 is placed in a storage bag for disposal such as a vinyl bag. There is a possibility that the work of transferring the toner will become difficult, and that the waste toner will adhere to the inner wall of the collection container 14. In order to solve such a problem, the toner removed from the transfer / conveyance belt 4 during the image forming operation and the water containing the corona product at the time of removing the corona product by the liquid application are put into separate recovery containers. It is desirable to collect.

FIG. 2 is a front view showing a schematic structure of an electrophotographic copying machine having such a structure. In the electrophotographic copying machine according to the present embodiment, the transfer / conveyance belt 4 is rotationally driven in the direction opposite to the arrow D direction during the image forming operation when the corona product is removed by the liquid application, and the application device 12 is used. The arrangement with the cleaning blades 13 and 14 is reversed from the example shown in FIG. 1, so that the surface of the transfer / conveyance belt 4 coated with water is the photosensitive drum 1 as in the above case.
After being opposed to the surface, it is cleaned by the cleaning blade 13. Then, below the cleaning blade 13, a collection container 14 for the removed toner during the image forming operation is performed.
a and a recovery container 14b for water containing the corona product at the time of removing the corona product by liquid application are separately provided.
The other points are the same as those of the above-described embodiment, and corresponding members are designated by the same reference numerals in the drawings.

In the above construction, the coating roller 11 is retracted from the surface of the transfer / conveyance belt 4 during the image forming operation as in the above embodiment. Then, the cleaning blade 13 counter-contacts the surface of the transfer / transport belt 4 rotating in the direction of the arrow D to scrape off the adhered toner, and the toner removed by scraping falls into the toner collecting container 14a and is collected. .. On the other hand, at the time of removing the corona product by liquid application, the application roller 11 is moved to a position in contact with or close to the surface of the transfer / transport belt 4 to transfer the water in the storage container 10 to the surface of the transfer / transport belt 4 as in the above embodiment. Then, the corona product on the photosensitive drum 1 is removed while the transfer / conveyance belt 4 coated with water is rotated in the direction opposite to the arrow D direction. The cleaning blade 13 makes trailing contact with the surface of the transfer / transport belt 4 to scrape off the water containing the corona product on the surface of the transfer / transport belt 4, and the water containing the corona product removed by scraping is:
It is dropped and collected in a water collecting container 14b containing a corona product.

Contrary to the example shown in FIG. 2, the cleaning blade 13 is brought into trailing contact with the surface of the transfer / conveyance belt 4 which moves in the D direction during the image forming operation, so that the corona product generated by the liquid application is formed. It may be arranged so as to make counter-contact with the surface of the transfer / transport belt 4 which moves in the opposite direction to the D direction at the time of removal. Further, the cleaning blade 13 itself is used for removing toner from the surface of the transfer / transport belt 4 during the image forming operation, and water containing the corona product from the surface of the transfer / transport belt 4 during removal of the corona product by liquid application. Separately from the collection containers 14a, 14
It may be arranged corresponding to each b. In this case, a mechanism for retracting from the surface of the transfer / transport belt 4 when not using each cleaning blade is provided.

[0019]

According to the present invention, at the time of non-image formation, a liquid for removing corona products on the surface of the image carrier by the application means on the surface of the carrier belt which is in contact with or close to the surface of the image carrier of the conveyor belt device. Since the liquid is applied to the surface of the image carrier through the surface of the conveyor belt, the liquid application device can be provided without increasing the size of the image carrier. Further, during non-image formation, if the surface of the image carrier and the surface of the above-mentioned conveyor belt are driven so as to have a relative speed at the contact portion, corona products can be satisfactorily removed from the surface of the image carrier. Further, a driving unit that moves the conveyor belt in a direction opposite to that in image formation during non-image formation, a collection container that collects the removed material removed from the surface of the conveyor belt by the cleaning unit during image formation, and a non-image By providing a collection container for collecting the removed material removed from the surface of the conveyor belt by the cleaning means at the time of formation, the toner removed from the surface of the conveyor belt by the cleaning means during the image forming operation,
Since the liquid containing the corona product removed from the surface of the conveyor belt by the cleaning means at the time of non-image formation is collected in separate collecting containers, the collected toner does not mix with the liquid and adhere to the inner wall of the collecting container.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of an electrophotographic copying machine according to an embodiment.

FIG. 2 is a front view showing a schematic configuration of an electrophotographic copying machine according to another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photoconductor drum, 4 Transfer / conveyance belt 5 Transfer paper, 10 Storage container 11 Coating roller, 12 Coating device 13 Cleaning blade, 14 Collection container

Claims (3)

[Claims] 1. An image forming apparatus for repeatedly using an image carrier surface for image formation while applying corona discharge to the surface of an image carrier that is moved endlessly for charging / discharging. A conveyor belt device for conveying, a cleaning means for cleaning the surface of the conveyor belt, and a corona product removal on the surface of the image carrier on the surface of the conveyor belt which is in contact with or close to the surface of the image carrier of the conveyor belt during non-image formation. An image forming apparatus, comprising: an applying unit that applies a liquid for use. 2. The image forming apparatus according to claim 1, further comprising driving means for driving the surface of the image carrier and the surface of the conveyor belt so that they have a relative speed at a contact portion during non-image formation. 3. A drive means for moving the conveyor belt in a direction opposite to that during image formation during non-image formation, and a collection container for collecting the removed material removed from the surface of the conveyor belt by the cleaning means during image formation. The image forming apparatus according to claim 1, further comprising: a recovery container that recovers the removed material removed from the surface of the conveyor belt by the cleaning unit during non-image formation.