JPH0954482A - Image forming device and wire cleaning device for electrifier thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute cleaning without retreating an electrifier from a surface to be electrified by constituting a wire cleaning member of a sheet-like member and arranging the cleaning member so that plural wires may be alternately positioned on an image carrier side and an opposite side thereto. SOLUTION: In one web 6, grid wires 5 are arranged every other wire so that the inside (electrifying wire side) and the outside of the wire 5 may be alternately woven. In the other web 6', the wires 5 are arranged to be woven every other wire in the same manner as the web 6 but arranged so that its position with respect to a grid may be reversed inside and outside to the web 6. When a motor 11 is driven according to a cleaning command, a slider 9 and a projected part 10 previously set in a specified area move the webs 6 and 6' disposed thereon in a direction E. Thus, both inner and outer surfaces of the wire 5 are cleaned by rubbing and both inner surfaces of a shielding case 3 are also leaned.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrostatic copying machine or a printer, and more particularly to a cleaning device for a charging device thereof.

[0002]

2. Description of the Related Art In a known image forming apparatus of this type, when an electrostatic back image is formed on an image carrier, a toner image on the image carrier is transferred to a transfer material. For example, a charging means is required to apply an electric charge to the surface of the image bearing member, which is the surface to be charged, and the surface of the transfer material.

As charging means for this purpose, a charging wire is stretched so as to face the surface to be charged in a shield race which is conventionally open on the surface to be charged, and a bias voltage is applied to the charging wire. Therefore, it is well known that the shield case opening portion, the one having the grid disposed between the charging wire and the surface to be charged, etc. are widely used.

By the way, the toner used in this type of image forming apparatus is extremely fine and lightweight particles.
It is extremely difficult as a practical matter to contribute this toner in a completely sealed state to the image formation in all the steps of image formation in the apparatus. It is inevitable that foreign matter such as fine paper dust generated, rosin and talc deposits, etc. are present in a floating state.

If such floating toner or other foreign matter adheres to the charging wire, grid or the like of the charger, uneven charging or defective charging may occur on the surface to be charged, which may lead to deterioration of image quality. there were.

Recently, various image forming apparatuses have been proposed in which two types of latent images are formed on one image carrier and the latent images are developed with toners of the same or different colors. FIG. 7 is a schematic side view showing an example of such an image forming apparatus. To briefly describe the configuration thereof, the image carrier 1 having an axis line in the direction perpendicular to the plane of the drawing and rotating in the direction of the arrow shown in the drawing. Close to the first charger 30, the image signal applying portion L1, the first
Developing devices 40 are arranged in this order, and the second charging device 60, the image signal applying portion L2, and the second developing device are provided on the downstream side of the first developing device 40 in the running direction of the image carrier. 70 is provided. The image forming process using each member is the same as that of a known device.

In such an image forming apparatus, since the second charging device 60 is arranged immediately downstream of the first developing device 40, the toner leaked from the first developing device 40 and the image bearing member are leaked. It is inevitable that the second charger 60 will be significantly contaminated as compared with a normal charger due to the dropping of the toner that has not been formed.

On the other hand, various cleaning means for the charging wire of the charging device have been proposed in the past, but all of them have usually utilized the space inside the charging device. At the same time, when it comes to cleaning the grid, the grid is usually arranged outside the open side of the shield case of the charger, and it is necessary to clean the grid surface facing the surface to be charged. For,
The cleaning means must be located outside the charger.

However, since the distance between the grid and the surface to be charged is usually as small as about 1 mm, it is not easy to dispose a cleaning member between the surface to be charged and the grid surface facing the surface. Therefore, there is a method of separating the charging device from the surface to be charged at the time of cleaning, but this requires a retracting mechanism of the charging device, which requires a space therefor and leads to an increase in cost, which is not preferable.

The amount of foreign matter adhering to the clid etc. is
The contact pressure of a cleaning member such as a sponge or web to the grid is adjusted so as not to adversely affect the life of the grid due to excessive wear of the grid, since the contact pressure of the cleaning member such as a sponge or a web varies depending on the usage environment, usage mode, etc. There is a need.

Furthermore, as the image forming apparatus has become faster and more multifunctional in recent years, the charging device tends to be rapidly contaminated, which may lead to a situation in which replacement by a service person or a user cannot make it in time. . To deal with this, it is necessary to activate the cleaning part as much as possible.

The present invention has been made to cope with such a situation, and in cleaning a plurality of wires such as a grid of a charger of an image forming apparatus, sheet-like cleaning members are alternately laid over adjacent wires. It is not necessary to retract the charger from the surface to be charged during cleaning by rubbing and cleaning in the longitudinal direction, and the contact pressure on the wire can be adjusted by adjusting the tension of the cleaning member. Further, there is provided a cleaning device for a charging device, which enables the cleaning member to be successively wound, and allows a portion having a good cleaning function to come into contact with a member to be cleaned at all times to maintain a high cleaning function. That is the purpose.

[0013]

Configuration of the Invention

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a wire cleaning apparatus for an image forming apparatus which comprises a running image carrier and a plurality of wires arranged in parallel in parallel to the surface of the image carrier. In the apparatus, the cleaning member for the wire is a sheet-like member, and the cleaning member is arranged so that the plurality of wires are alternately located on the image carrier side and the opposite side. In the wire cleaning device (1) or the above (1), at least two cleaning members are arranged in the longitudinal direction of the wires, and one cleaning member is positioned on the image carrier side of each wire. The cleaning member so that the portion located on the side opposite to the image carrier and the portion located on the side opposite to the image carrier correspond to the portion located on the side opposite to the image carrier and the portion located on the side opposite to the image carrier. In the wire cleaning device (2) of the image forming apparatus characterized in that the cleaning member is movable in a longitudinal direction of the wire to be cleaned. A wire cleaning device (3) for an image forming apparatus, or the above (1)
In any one of (3) to (3), a storage part of an unused cleaning member is provided at one end of the cleaning member, and the unused cleaning member in the storage part is located at a position where the unused cleaning member is engaged with the wire to be cleaned as needed. In the wire cleaning device (4) of the image forming apparatus, which is provided with a moving means, or in any one of the above (1) to (4), the tension of the cleaning member engaging with the wire to be cleaned. In the wire cleaning device (5) of the image forming apparatus or any of the following containers (1) to (5), the wire cleaning member is a grid of charging means. A wire cleaning device (6) of an image forming apparatus, or an image carrier that runs, a first charging unit that charges the image carrier, and an electrostatic latent image formed on the charged surface of the image carrier are developed. First developing means In an image forming apparatus provided with a second charging unit and a second developing unit arranged downstream of the first developing unit in the running direction of the image carrier, a grid cleaning of the second charging unit is provided. As means (6) above
An image forming apparatus comprising the wire cleaning device described above.

With this structure, it is possible to easily and surely clean the charger of the charger arranged in the vicinity of the image carrier, especially the grid located very close to the image carrier.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS "FIG. 1" to "FIG. 3" are the first of the present invention.
FIG. 1 is a side view in which the charger 2 is arranged in parallel to the image carrier 1 normally formed in the shape of a rotating cylinder and close to the surface thereof. FIG. 2, “FIG. 2” is a plan view of the release side facing the image carrier 1, and “FIG. 3” is a sectional view.

The charger 2 is provided with a shield case 3 having a substantially U-shape with the image carrier 1 side as a release side, and the charging wire 4 is provided inside the shield case 3 in the longitudinal direction (see FIG. 3). ) Is extended, and a bias voltage is applied to it by a power source (not shown). An appropriate number of grid wires 5 are extended in the longitudinal direction on the release side of the shield case 3 of the charger, and the wires 5 oppose the surface of the image carrier at a position very close to the surface. To do.

A slider guide 7 and a screw rod 8 are arranged on the opposite side of the charger 2 from the image carrier 1 in parallel with the shield case. Slider guide 7 has slider 9
Are engaged with each other, and the slider 9 is screwed onto the screw rod 8. Further, at the end of the screw rod 8, a forward / reverse rotatable motor 11 is provided. Therefore, when the slider 9 is in the area G outside the image area of FIG. 1, the slider 9 is moved in the direction E in the figure by driving the motor 11, and the area H outside the image area on the opposite side. Reached
By rotating the motor 11 in the reverse direction,
You can move in the direction and bring it to the old place.

The slider 9 has a pair of protrusions 10 and 10.
Is provided (see "FIG. 2"), and in this case, two cleaning webs 6 and 6'are provided in this portion. These cleaning webs 6 and 6 ′ have one protrusion 1
It extends from 0 and is suspended so as to reach the other protrusion via the grid 5 portion as shown in FIG.

As can be seen from FIGS. 2 and 3, one web 6 has every other grid wire 5 inside (on the charging wire side) and outside (on the image carrier 1) of the wire. Opposite sides) are arranged to interweave each other and the other web 6 ′ is arranged to weave every other wire 5 in the same manner as the web 6, but the web 6 is a position relative to the grid. Are arranged so that they are opposite inside and outside.

Since the webs 6, 6'are arranged in this way, when they move with the slider 9,
The grid wire 5 stretched on the open side of the shield case
One of the webs is rubbed on the inside and the other web is rubbed on the outside.

Further, as can be seen from FIG. 3, the webs 6 and 6 ′ suspended from the one protrusion 10 toward the other protrusion 10 via the grid wire 5 are the protrusions 10. It is arranged so that the portion located between the grid wire 5 and the grid wire 5 contacts the inner surface of the shield case 3.

With such a structure, when the motor 11 is driven by the cleaning command, the webs 6, 6'disposed on the slider 9 and the projection 10 in the area G in advance are removed. As described above, by moving in the E direction, the inner and outer surfaces of the grid wire 5 are rubbed and cleaned, and both inner surfaces of the shielded case 3 are also cleaned. When the slider 9 reaches the area H, the motor 11 reversely rotates and the above cleaning operation is repeated, and when the slider 9 returns to the area G, the motor 11 stops.

As described above, according to this apparatus, when cleaning the grid wire of the charger, the portion of the wire protruding outside the charger for cleaning the outer surface of the wire facing the image carrier is extremely small. In order to clean the grid wire portion, it is not necessary to retract the charger from its operating position, there is no need for an auxiliary mechanism such as driving means therefor, and the shield case can be cleaned at the same time.

FIG. 4 is a sectional view of the essential part showing another embodiment. The overall structure of the charger and the operation thereof are basically the same as those of the above-mentioned embodiment, and therefore the description thereof will be omitted.

In this apparatus, the slider 9 is guided by one slider guide 7, and a tension guide 7'is arranged at a position corresponding to the other slider guide in the apparatus of the above embodiment. The tension guide 7'is fitted in a long hole 12 provided in the slider 9 and extending in a direction substantially coinciding with the radial direction of the image carrier 1, and an actuator (not shown) serves as a symbol J in FIG. -It shall be possible to move in the I direction.

The slider 9 lacks one slider guide 7 for guiding the slider 9 as compared with the above-mentioned embodiment apparatus, but even in this apparatus, the slider 9 has the slider guide 7.
Since it is supported by the screw rod 8, the shield case 3 can be moved to a predetermined position without any trouble.

During operation of the image forming apparatus, the tension guide 7'moves in the direction of arrow J and the webs 6 and 6'are not tensioned. When the sensor (not shown) detects the attachment of the foreign matter to the grid wire in the state where the image forming operation is stopped, the tension guide 7 ′ moves in the direction of the reference numeral I to apply tension to the webs 6 and 6 ′. In this state, the web is moved in the same manner as in the case of the above-described apparatus to clean the grid.

After the cleaning is completed, the result after cleaning is again compared with the state before cleaning by the sensor, and the tension of the webs 6 and 6'is appropriately set according to the degree of the cleaning effect to obtain the tension for the next cleaning. By doing so, the tension of the web can be set according to the cleaning result, so that the grid wire can be optimally cleaned.

FIGS. 5 and 6 show still another embodiment. FIG. 5 is a sectional view of the charger, and FIG. 6 is a plan view of the main part as seen from the grid side. . The basic structure of the charging device, such as the slider 9 which reciprocates in the longitudinal direction of the charging device and cleans the grid wire by the webs 6 and 6 ', is not particularly different from that shown in FIGS. .

In this apparatus, protrusions 9a and 9b are formed on both sides of the slider 9, and the pulleys 13 arranged on the protrusions 9a have cleaning webs 6 and 6 '(only one of which is shown in the drawing). Is shown) is wound and stock 6s
Is formed.

Web 6, 6'from the stock 6s
Travels along the inner surface of the shield case 3 as in the apparatus of the above-described embodiment, and the webs 6 and 6'are arranged so as to be alternately located on the inner and outer surfaces of the wire 5 at the position of the grid wire 5. Then, it reaches the pulley 14 along the inner surface of the other shield case.

FIG. 6 is a plan view of the slider 9 at the home position as seen from the grid side. As can be seen from this figure, a one-way clutch 16 is arranged at the end of the pulley 13 which supports the stocks 6s and 6's on which the webs 6 and 6'are respectively wound, and a motor 15 is arranged at the other pulley 14. It is set up. Therefore, by driving the motor 15, each web 6, 6 ′ is sequentially moved to the pulley 1
4, and the new side of the web comes into contact with the grid wire 5.

In the state where the image forming operation is stopped, when a sensor (not shown) detects a certain amount or more of foreign matter on the webs 6, 6 ', or when a counter or the like detects a certain number of image formations. A position where the sleeping motor 15 is driven to rotate the pulley 14 to move the webs 6 and 6 ′ in the direction K (“FIG. 6”) to bring the unused web in the stocks 13 and 13 into contact with the grid wire 5. I will bring it to the factory, and after that I will carry out cleaning with this part. As a result, the grid wire can be constantly cleaned by a portion having a high cleaning ability.

[0034]

As described above, according to the present invention,
In an image forming apparatus equipped with a charger arranged close to an image carrier, a grid wire of the charger is provided over the entire length,
In addition, it is possible to clean almost the entire surface in the circumferential direction, and even the inner surface of the shield case of the charger can be cleaned. If necessary, the contact action of the cleaning web with the grid wire can be adjusted. Since the cleaning ability can be adjusted and the cleaning can always be performed by the part of the cleaning member having a high cleaning function, it largely contributes to the stabilization of the function of the charger and is a significant effect in obtaining a high quality image. There is.

[Brief description of drawings]

FIG. 1 is a side view of a charger showing an embodiment of the present invention.

FIG. 2 is a plan view seen from the grid wire side.

FIG. 3 Same as above

FIG. 4 is a sectional view of a charger showing another embodiment.

FIG. 5 is a sectional view of a charger showing still another embodiment.

FIG. 6 is a plan view of the main part of the same charger as above.

FIG. 7 is a schematic side view showing the configuration of a known image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image carrier 2 Charging device 3 Shield case 4 Charging wire 6, 6'Cleaning web 7 Slider guide 8 Screw rod 9 Slider 10 Projection part 11, 15 Motor 13,14 Pulley 16 Clutch

Claims (7)

[Claims] 1. A wire cleaning device of an image forming apparatus comprising a running image carrier and a plurality of wires arranged in parallel in parallel to the surface of the image carrier, wherein the wire cleaning member comprises a sheet-shaped member. Is arranged so that the plurality of wires are alternately located on the side of the image carrier and on the side opposite to the side of the image carrier. 2. At least two cleaning members are arranged in the longitudinal direction of the wire, and for each wire, a portion of one cleaning member located on the image carrier side and a portion located on the opposite side of the image carrier. However, the cleaning member is arranged so as to correspond to a portion of the cleaning member adjacent to the cleaning member and a portion of the cleaning member located on the side opposite to the image bearing member and a portion of the cleaning member positioned on the image bearing member side, respectively. A wire cleaning device for an image forming apparatus. 3. A wire cleaning device for an image forming apparatus according to claim 1, wherein the cleaning member is movable in the longitudinal direction of the wire to be cleaned. 4. A cleaning member is provided at one end thereof with a storage portion for the unused cleaning member, and means is provided for moving the unused cleaning member at the storage portion to a position for engaging the wire to be cleaned, if necessary. The wire cleaning device for an image forming apparatus according to any one of claims 1 to 3, characterized in that: 5. A wire cleaning apparatus for an image forming apparatus according to claim 1, further comprising means for changing a tension of a cleaning member that engages with the wire to be cleaned. apparatus. 6. The wire cleaning device for an image forming apparatus according to any one of claims 1 to 5, wherein the wire cleaning member is a crid of a charger. 7. A running image carrier, first charging means for charging the image carrier, first developing means for developing an electrostatic latent image formed on the charged surface of the image carrier, and an image. In an image forming apparatus including a second charging unit and a second developing unit arranged on the downstream side of the first developing unit in the running direction of the carrier, a grid cleaning unit of the second charging unit. An image forming apparatus comprising the wire cleaning device according to claim 6.