JPS61140964A - Cleaning device of corona discharger - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a developing function and copy image quality by rotating a photosensitive body opposite from the turning direction thereof and removing the dirt dropping on the photosensitive body by a cleaner. CONSTITUTION:A shaft 16 of a cleaning member is first slid and a yoke 8 is moved along a corotron wire 7 of a corona discharger 2 to clean the wire 7 of said discharger. The dirt sticking on the surface of the wire 7 is then scraped by a cleaning pad 9 fitted to the yoke 8 and is dropped onto the surface of a photosensitive drum 1. The drum 1 is then rotated in the backward direction to convey the dirt on the drum 1 into the cleaner 3. The dirt is discharged into a toner recovering vessel 24 by acting the cleaner 3, by which the wire 7 is cleaned. The dirt scraped from the wire 7 surface is prevented from being carried into a developing device 26 and therefore the deterioration of the developing function of the device 26 by the dirt and the deterioration of the copy image quality are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a corona discharger used in electrophotographic copying machines and the like, and particularly to a cleaning device for this corona discharger.

[Conventional technology]

Conventionally, in an electrophotographic copying machine, as shown in FIG. This latent image is developed with toner using a developer (dl) to form a toner image (e), and then this toner image (e) is transferred to paper ( g) At the same time, this paper (g) is peeled off from the photoreceptor (al) using a paper peeling corona discharger (hl), and the toner is fixed using a fixing device (i) to obtain a copy. There is.

On the other hand, after the paper (g) has been peeled off, the photoreceptor (al) is neutralized by a static eliminating corona discharger (j) if necessary, and the toner remaining on its surface is removed by a cleaner (kl).
It is constructed so that it can be removed and reused.

In this way, the corona discharger is used as a charging and neutralizing device for the photoreceptor (a), a transfer device for toner (a (el), and a peeling device for paper (gl). Its configuration is shown in Fig. 7. As shown in the figure, it generally consists of a shield with a roughly U-shaped cross section that is open on the photoreceptor side, and a discharge wire (ml) that is stretched inside this shield and generates corona ions. In the corona discharger for
If necessary, as shown in FIG. 8, a grid (n) is attached to the shield (phantom open end side) and
The structure is such that one surface can be uniformly charged.

By the way, in this corona discharger, contaminants such as floating toner inside the copying machine and gas products accompanying discharge tend to adhere to the shield (1), the discharge wire h) or the grid (nl, etc.), and as a result, the discharge function is impaired. The disadvantage was that it decreased.

In other words, in a corona discharger equipped with a grid (nl), as shown in FIG. This is because floating toner and the like are easily attracted to the grid (n) due to this strong electric field.

This grid (n), due to its electric field,
This equalizes the excess or deficiency of the potential of the photoreceptor (a).
Because it has the effect of forming a uniform copy image on the
When this is contaminated, the potential increases in that area and the electric field becomes larger, which causes the potential of the photoreceptor (a) corresponding to that area to rise, resulting in a locally high image density. Met.

In addition, dust such as toner powder easily adheres to the discharge wire (), and products mainly composed of silicon also adhere to the adsorption phenomenon accompanying corona discharge, so the amount of corona ions generated from the discharge wire decreases. This had the disadvantage that the discharge function deteriorated.

For this reason, as shown in Figure 9, the above shield (inside the illusion,
A cleaning device (p) is provided, which is equipped with a cleaning pad (o) made of rubber, non-woven fabric, etc., and in which this pad (o) is brought into pressure contact with the outer peripheral surface of the above-mentioned discharge wire), etc. ?The above-mentioned disadvantages are prevented by sliding it along the discharge wire and scraping off dirt such as toner powder adhering to the outer circumferential surface of the discharge wire (NL) and the like.

[Problem that the invention seeks to solve]

However, in the corona discharger equipped with this cleaning device (p), the dirt scraped off from the discharge wire 6m1 etc. by the cleaning operation is removed from the photoreceptor (p).
Since the filth falls onto the Al, if the fallen filth is left as it is, it has the drawback of causing various problems as shown below.

That is, the main component of the dirt is a developer such as toner, but since it has been altered by the discharge of the discharge wire, it coagulates with each other and becomes large particles.

Therefore, if the dirt on the photoreceptor (a) is left as it is, the dirt will be transported into the developing device (al) when the photoreceptor (al) rotates in the direction of arrow A. Because it is stored away (see Fig. 6), it has the drawback of clogging in the developing device (DL) and deteriorating the developing function.

Furthermore, if part of the dirt conveyed into the developing device (d) adheres to the photoreceptor (a) again during the developing process and is conveyed onto the paper (g), it may be mixed with other normal developer. In comparison, the dirt mentioned above has different charging characteristics, so it is easily transferred onto the paper (gl) regardless of the electrostatic latent image on the photoreceptor (a), and as a result, fogging etc. occur and the quality of the copied image is significantly reduced. There were drawbacks that caused it to deteriorate.

e Means and operation for solving the problem] The present invention was made in view of the above circumstances, and is based on a corona discharger equipped with a cleaning device, and the cleaning operation removes the chips from the discharge wire, etc. It is an object of the present invention to provide a cleaning device for a corona discharger that prevents removed dirt from being transported into a developing device, thereby preventing deterioration of the developing function and copied images.

That is, the present invention includes a photoconductor that rotates in a certain direction, a cleaner that is disposed near the photoconductor and that removes and cleans toner remaining on the surface of the photoconductor, and a cleaner that is disposed adjacent to the cleaner. , a corona discharger having a shield whose lower side is open and a discharge wire stretched therein to charge the surface of the photoreceptor cleaned by the cleaner; A cleaning member is installed in this shield to remove dirt such as toner adhering to the discharge wire and drop it onto the photoreceptor. The rotating direction of the photoreceptor is reversed and removed by the cleaner, thereby preventing the dirt from being conveyed into the developing device, thereby preventing deterioration of the developing function and copy image quality.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the corona discharger (2) is disposed near a photosensitive drum (1) that is rotatable in the forward and reverse directions by a motor (not shown), and this discharger. (2) a cleaning member (not shown) provided in the corona discharger (2);
A cleaner (3) provided adjacent to the photosensitive drum (1), and a reversing member (not shown) for reversing the rotational direction of the photosensitive drum (1).

First, the corona discharger (2) includes a shield (4) made of a conductive material having a substantially U-shaped cross section, as shown in FIG.
Wire attachment members (5) fi+ arranged on both ends of this
and a corotron wire (7) stretched over this mounting member f5) f6), and a yoke (8) inside the shield (4) and a corotron wire (7) that is attached to this yoke (8). A cleaning member consisting of a cleaning pad (9) with a cylindrical surface and a cylindrical cleaning pad (9) is provided. In FIG. 2, the front side surface of the shield (4) is omitted from illustration in order to facilitate understanding of the present invention.

As shown in FIGS. 2 and 3, the yoke (8) is formed on its upper surface side parallel to the width direction of the shield (4), and has a roughly shaped cross section into which the cleaning pad (9) is fitted. A letter-shaped groove (10) and the front wall of this groove αΦ (
11) and the rear wall (12), a substantially U-shaped notch recess (13) for passing the corotron wire (7).
) (14), and a convex portion (not shown) provided on the bottom side of the shield (4) is connected to the guide 05) provided on the bottom surface of the shield (4). It is arranged so that it fits loosely.

Further, a shirt l-(16) provided loosely through the wire attachment member (5) is attached to the lower side of the front wall (11) of this yoke (8).
) is formed so as to move along the length of the shield (4) by mechanically or manually sliding the yoke (8).

In addition, the cleaning pad (9) fitted on this yoke (8) is made of two cleaning materials (1
7) The corotron wire (7) is inserted between the cleaner material (17) and (18), and the cleaner material (17) (
18) is attached so that it can slide along the wire (7) with a predetermined frictional force by bonding the contact surface thereof.

On the other hand, the cleaner (3) has two fur brushes (19) and (20) disposed near the photosensitive drum (1) as shown in FIG.
a cylindrical conveying member (21) for conveying the residual toner removed by the above-mentioned A cyclone filter (23) provided at the distal end of the conveyance member (21), and a toner collection container (2) attached to the lower side of the cyclone filter (23).
4).

Further, the photosensitive drum fil is configured to be rotatable in forward and reverse directions by a motor (not shown), and rotates in the direction of arrow A during the copying process, while the corona discharger (2
) When operating the cleaning member, it is configured to rotate in a direction opposite to the direction A by the action of a reversing member (not shown).

In Fig. 1, (25) is the optical system, (26) is the developing device, and ω.
7) indicates a fixing device, and (28), (29), and (30) indicate corona dischargers for toner transfer, paper peeling, and static elimination, respectively.

Then, by using the cleaning device of the present invention, a corona discharger (
To completely clean the corotron wire (7) in step 2), first slide the shaft (16) of the cleaning member to move the yoke (8) along the t-corotron wire (7), and then remove the yoke ( The dirt adhering to the surface of the wire (7) is scraped off by the cleaning pad (9) fitted onto the wire (8) and dropped onto the surface of the photosensitive drum (1).

Next, the reversing member is activated to rotate the photosensitive drum (1) in the direction opposite to the direction of arrow A to transport the dirt on the photosensitive drum (1) into the cleaner (3). ) to discharge the dirt into the toner collection container (24) and clean the corotron wire (7).

Therefore, in the cleaning device of the present invention, the dirt scraped from the surface of the corotron wire (7) is removed from the developing device (
26), it is possible to prevent the deterioration of the developing function of the developing device (26) and the deterioration of the copy image quality caused by the filth.

In the above embodiment, the cleaning member cleans only the corotron wire 17) inside the shield (4), but as shown in FIG. , a cutout recess (3υ) with a cross-sectional shape parallel to the length direction of the shield (4) is formed, and this recess (31) (31) and the shield (4)
By interposing the cleaner material (32) (32) fif between the bottom surfaces, the bottom surface side of the shield can also be cleaned.

Further, although the corona discharger of the above embodiment is of a type without a grid on the open end side of the shield (4), the present invention can also be applied to a corona discharger equipped with a grid.

That is, as shown in FIG. 5, a grid (33) is sandwiched between two pieces of cleaner material (34) (35) from both sides, and the cleaner material (34) (35) is attached with adhesive.
5] to form a cleaning pad (36), and this pad (36) is fitted into the groove (38) of the second yoke (37), which has an engaging recess (not shown) on the bottom side. ,
And this second yoke (37) 1 &: A yoke (
8) may be configured to be detachably attached.

Further, in the above embodiment, a cleaning pad is used as a cleaning member, but it may be replaced with a system using an ultrasonic vibrator, and the cleaner (3) is also used as a fur brush (19) (20 ), other magnetic brush systems or blade systems may be adopted, and the configuration is arbitrary.

Furthermore, the present invention can of course be applied not only to photosensitive drum type copying machines but also to photosensitive belt type copying machines.

〔Effect of the invention〕

As described above, the present invention provides a corona discharger that is disposed adjacent to a cleaner that removes and cleans toner remaining on the surface of a photoreceptor, in which dirt adhering to the discharge wire is removed within the shield. A cleaning member is provided to drop onto the photoreceptor, and the dirt is removed by the cleaner by reversing the direction of rotation of the photoreceptor, so that the dirt is not carried into the developing device. There is no.

Therefore, the deterioration of the developing function of the developing device due to the above dirt,
It also has the effect of preventing deterioration of copy image quality.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention. FIG. 1 is an explanatory diagram of the configuration of a copying machine incorporating the cleaning device of the present invention, and FIG. 2 shows a corotron wire inside the shield (4). FIG. 3 is a perspective view of the corona discharger according to the present invention in a state where (7) is installed, and the corona discharger is disposed within this shield (4).
FIG. 4 is a perspective view of a yoke (8) fitted with a cleaning pad (9), FIG. 4 is a partial sectional view of the yoke, FIG. 5 is a perspective view of a cleaning member according to another embodiment, and FIG. 7 to 9 are perspective views of a conventional corona discharger. [Code explanation]

Claims (1)

[Claims] A photoconductor that rotates in a certain direction, a cleaner that is disposed near the photoconductor and cleans it by removing toner remaining on the surface of the photoconductor, and a cleaner that is disposed adjacent to the cleaner and whose lower side is open. In the copying machine, the corona discharger has a shield with a shield and a discharge wire stretched therein to charge the surface of the photoreceptor cleaned by the cleaner. A cleaning member is provided to remove dirt such as toner adhering to the discharge wire and drop it onto the photoreceptor, and a cleaning member is provided to remove dirt such as toner adhering to the discharge wire and drop it onto the photoreceptor. A cleaning device for a corona discharger in a copying machine, characterized in that the cleaning device removes the corona discharger with the cleaner by reversing the moving direction.