JPH01164983A - Cleaning device for photosensitive body - Google Patents

Abstract

PURPOSE:To maintain cleaning performance at a high level for a long period by cutting both planes of the tip of a conductive brush that is a toner stirring means fitting in the plane of a photosensitive body and the plane of a cleaning blade, and impressing a voltage on the conductive brush. CONSTITUTION:The tip of the conductive brush 10 is cut fitting in the surface of the photosensitive body 1 and that of the cleaning blade 2, and the brush 10 is brought into contact with the photosensitive body 1 and the blade 2 at the tip of the brush. Therefore, a toner scraped from the surface of the photosensitive body 1 is stirred mechanically by the brush 10, and also, the voltage is impressed, and an attractive force by an electrostatic force is eliminated, then, drops, thereby, no toner is accumulated at a wedge shape part between the photosensitive body 1 and the blade 2. In such a way, no toner remains on the photosensitive body 1 or the blade 2 at the time of separating the blade 2 from the photosensitive body 1, and the periphery of an image forming body is not stained, and also, no toner is attached on the blade 2 extending over the long period, thereby, the cleaning performance can be stabilized and kept at the high level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a photoconductor cleaning device for an electrophotographic apparatus, and particularly to a photoconductor cleaning II! of the type in which a cleaning blade is brought into pressure contact with a rotating photoconductor! ! Regarding.

[Prior Art] Conventionally, as a means for cleaning toner after transfer from an image forming body of an electrophotographic apparatus, that is, a photoreceptor, an hour wheel IIA structure and a blade cleaning method with high cleaning efficiency have been used. There is. FIG. 7 is a diagram schematically showing the blade cleaning method.

In the figure, 1 is a cylindrical photoreceptor that rotates in the direction of the arrow. 2 is a cleaning blade made of polyurethane or the like, and 3 is a toner collection roller.

When cleaning*, the cleaning blade 2 advances to the right in the figure, brings the end corner into contact with the surface of the photoreceptor 1, as shown by the dotted line, and scrapes off the toner remaining on the surface. , toner image in the process of being formed (first color toner image,
When toner images of the second color, etc.) pass, these toner images must not be disturbed, so they are retreated to the position indicated by the solid line.

During cleaning, the toner scraped off by the cleaning blade 2 falls downward and is collected by a toner collection roller 3 located below toward a toner pool.

However, in such a configuration, when the cleaning blade 2 is retracted, a portion of the toner scraped up by the cleaning blade 2 may pass through the cleaning device while remaining attached to the photoreceptor 1.
Toner that has been scraped off by the cleaning blade 2 and is falling often adheres to the surface of the photoreceptor 1 at the position where the cleaning blade 2 was in contact and at the position facing the toner collection roller, and the cleaning blade 2 is retracted. Due to this condition, cleaning defects may occur where the particles pass through the cleaning device without being scraped off.

The toner that could not be completely cleaned moves with the rotation of the photoconductor 1 and spreads or scatters to other parts of the photoconductor surface, causing the charger and developer disposed around the photoconductor 1 to be damaged. This may stain peripheral equipment such as the transfer device and the separator, which may impede the quality of the image.

Therefore, the inventors of the present invention have invented a means for cleaning the toner that has slipped through without being scraped off by the cleaning blade 2 during the retracting operation of the cleaning blade 2, and the present applicant is currently applying for a patent. (Special application Sho 6O-2330
19) FIG. 8 is a schematic diagram showing the invention of the above application.

The difference from FIG. 7 is that a cleaning roller 4 made of sponge is newly provided.

The cleaning roller 4 is made of urethane foam rubber,
Contacting the surface of the photoreceptor 1 while rotating it in the same direction as the rotation direction of the photoreceptor 1 (movements at the contact portion are in opposite directions),
Clean the cleaning blade 2 by wiping off the residual toner that came from the first step. Of course, like the cleaning roller 4b and the cleaning blade 2, they are designed to retreat when a 1-toner image that is being formed passes therethrough. Toner that has been wiped off by the cleaning roller 4 and adhered to its surface is scraped off by a scraper 5.

This cleaning roller 4 is provided for the above purpose, so that after the cleaning blade 2 is retracted, it comes into contact with the photoconductor 1 before the accumulated toner adhering to the photoconductor 1 arrives, and the cleaning blade When the photoreceptor 2 is retracted, the portion of the photoreceptor 1 facing the toner collection roller 3 continues to be in contact until it passes the cleaning roller 4, and then retracts.

Cleaning [Cola 4] in a real image forming device
Considering the spacing between the cleaning blade 2 and the toner collection row 53 and the circumferential distance of the photoreceptor 1, the cleaning roller 4 comes into contact with the photoreceptor 1 immediately after the cleaning blade 2 is retracted, and is retracted in a short time.

[Problems to be solved by the invention] The cleaning device described above (Patent Application No. 6O-2330
No. 19) shows the results by thoroughly cleaning the accumulated toner adhering to the photoreceptor when the cleaning blade is retracted.

However, in addition to the toner recovery device using the toner recovery roller, the mechanism becomes complicated due to the provision of a toner recovery device based on the cleaning roller, and the need for space to dispose the cleaning roller downstream of the cleaning blade. Further, there are other problems such as an instantaneous increase in driving load due to the sponge rubber material coming into contact with the surface of the image forming member.

The present invention has been made to solve the above-mentioned problems.The present invention has been made in order to solve the above-mentioned problems.In a photoconductor cleaning device having a cleaning blade formed in the shape of a drum and pressed against the circumferential surface of a rotating photoconductor, the present invention provides cleaning performance as a main function for toner. The purpose of the present invention is to provide a cleaning device for a compact image forming apparatus that maintains high image quality over a long period of time, prevents contamination of various devices installed around an image forming body, and forms high quality images over a long period of time. shall be.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a photoconductor cleaning device having a cleaning blade formed in a drum shape and pressed against the circumferential surface of a rotating photoconductor. A conductive brush is inserted into a wedge-shaped space formed by the blade and the photoreceptor, and moves relative to the cleaning blade and the photoreceptor, and the tip of the conductive brush serves as a toner stirring means. The conductive brush is cut according to the conductive brush, and a voltage is applied to the conductive brush.

[Function] The toner scraped off from the surface of the photoreceptor by the cleaning blade is mechanically disturbed by the toner agitating means and a voltage is applied to remove the adhesion force due to electrostatic force and fall, so that the wedge shape between the photoreceptor and the cleaning blade is formed. Toner does not accumulate in the area.

Therefore, when the cleaning blade leaves the photoreceptor, no toner remains on the photoreceptor or on the cleaning blade, and the area around the image forming member is not contaminated. Further, since toner does not adhere to the cleaning blade for a long period of time, the cleaning performance is maintained stably and high, and high quality images can be obtained over a long period of IIm. In particular, the tip of the conductive brush, which is the toner agitating means of the present invention, is cut to match the surface of the photoconductor and the cleaning blade, so the brush contacts the photoconductor and cleaning blade with the tip of the bristles, which improves toner removal performance. is high.

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

FIG. 1 is a sectional view showing the main parts of a color copying machine to which the present invention is applied, and FIG. 2 is an enlarged sectional view showing the cleaning device shown in FIG. 1 with the drive section removed.

In the figure, reference numeral 1 denotes a photoreceptor made of an organic optical semiconductor (OPC) laminated on a cylindrical conductive drum, which forms a color toner image while rotating in the direction of the arrow shown in the figure. That is, the surface of the photoreceptor 1 cleaned by the cleaning device 11 is uniformly charged by the charger 8, and is irradiated with Rade exposure 9 so as to form a charged latent image corresponding to the toner image of each color. is the developing device 12 (13, 14)
attached by. The above-mentioned charging exposure and development are repeated once for each color, thus three times for three colors. The above laser exposure is main scanned in the direction perpendicular to the page and combined with sub-scanning by drum rotation to form charged latent images corresponding to yellow, magenta, and cyan images on the photoreceptor surface, but the laser exposure is modulated. The image information for this purpose is provided by a conventionally known color separation image reading device and image processing device. In this way, a color toner image is formed on the photoconductor 1. To explain the time course, during the first rotation of the photoconductor 1, a charged latent image corresponding to the yellow toner created by the laser exposure 9 becomes yellow. Toner developing device 12
By applying direct current to the developing roller 12', a yellow toner image is developed on the surface of the photoreceptor 1''.In the second rotation of the photoreceptor 1, the magenta toner developing device 13 is activated in the same manner. Magenta toner is attached to the surface of the photoreceptor 1 by the developing roller 13'. Further, cyan toner is attached by the developing roller 14' of the cyan toner developing device 14 during the third rotation of the photoreceptor.

The color image thus formed on the surface of the photoreceptor is transferred by a transfer device 16 onto recording paper fed from a paper feeder 15. The transferred recording paper is separated by a separator 17 and then sent to a fixing device 18, where the three-color image is fixed on the recording paper. Since the three-color images are combined on the photoreceptor 1 and transferred onto the recording paper at once, a good image quality without color shift can be obtained. In the above process, the photoreceptor first passes through the cleaning device 11 while carrying a yellow toner image, and then passes through the cleaning device 11 while carrying yellow toner and magenta toner images. In this manner, the cleaning device 11 is deactivated whenever an untransferred image passes through, and the cleaning device 11 is activated at other times. The cleaning device will be explained below with reference to FIG. Reference numeral 2 denotes a cleaning blade constituting the main cleaning means, which is held by a holding device 20 that is driven to rotate about a shaft 19, and is brought into and out of pressure contact with the photoreceptor 1.

Reference numeral 10 denotes a YG electric brush material, which is toner agitating means, and is held by a holding member 21. The holding member 21 is driven to move linearly in the depth direction of the device, and is pressed against and retracted against the surface of the photoreceptor. is also driven. As shown in FIG. 6, the conductive brush material 10 has a tip cut to match the surface of the photoconductor and the cleaning blade, and the brush contacts the photoconductor and cleaning blade elastically at the tip. . Further, the 1lffi brush material 10 is configured to be applied with an AC voltage of 500V to 700V.

Reference numeral 23 denotes a brush squeezing member, which is a means for sufficiently sustaining the function of the brush.

Reference numeral 3 denotes a toner collection roller that constitutes a toner receiver, which is connected to the photoreceptor 1 with a gap (0) of about 0.2 to 0.3 feet and is rotated in the direction of the arrow, and is also driven by direct current. A positive voltage of about 500V is applied. A toner guide 6 guides the toner from above the toner collection roller 3 to the lower groove of the casing 22. 7 is rotated by a screw so that a spiral blade sends toner into a toner reservoir.

Next, to explain the operation of the cleaning device, as mentioned above, the cleaning device does not operate when an untransferred toner image passes, so the cleaning blade 2
It is held at a distance from the Immediately before the residual toner after transfer reaches a position facing the cleaning blade 2 of the cleaning device, the cleaning blade 2 is pressed against the photoreceptor 1 by the operation of the holding device. This state is maintained throughout the passage of the imaged portion. In this way, the residual toner is peeled off from the surface of the photoreceptor by the cleaning blade 2 and guided into the lower groove of the casing along the path shown by the arrow. That is, since the toner collecting roller 3 is applied with a voltage of opposite polarity to the toner, it attracts the toner and does not leak it downward.

The toner on the toner collection roller 3 is sent onto the toner guide 6 as the toner collection roller rotates.

Next, in this device, the cleaning blade is separated from the photoconductor after the residual toner in the same transfer pattern has passed, but at that time, the toner that had accumulated between the cleaning blade and the photoconductor remains on the photoconductor. Before the blade leaves the photoreceptor, the conductive brush material 10 enters toward this toner retention area to prevent the blade from leaving the photoconductor, and combines the mechanical peeling force due to the toner disturbance operation of the linear motion and the electric force of the AC voltage. Due to the combined effects of the above, the remaining toner is disturbed and removed, and the toner is almost completely removed from the surface of the photoreceptor and the back surface of the cleaning blade. The removed toner falls onto the toner collection roller 3 located below, and is sent to the toner guide 6 and collected by the aforementioned action. The brush can be inserted into the wedge-shaped space between the cleaning blade and the photoreceptor at any time after the blade is pressed into contact with it, and even when it is withdrawn, it will not cast a shadow on the leading edge of the toner image in the next copying process. Any time is acceptable as long as it is within the specified time. Additionally, voltage application can be switched on and off according to the process.

In other words, a voltage is applied when the conductive brush is inserted toward the toner retention portion, and no voltage is applied when the conductive brush is away from the photoreceptor.

Although the present embodiment uses an electric force based on an alternating current voltage, the invention is not limited to this, and a superimposed force of direct current and alternating current may be used.

Brush materials include carbon 1a fibers and conductive acrylic 1
11ft, and conductive rayon or conductive polyester having a resistance value of about 10<-3> to 10<10>[Omega].alpha. are particularly suitable for use.

Next, move the holding member 21 of the brush material 10! The 1II11 structure will be explained with reference to FIGS. 3 to 5.

The flat brush holding member 21 is supported by a slit provided in the casing 22 of the cleaning device so that it can freely move on a flat surface.

The holding member 21 moves forward and backward toward the photoreceptor 1 by the actions of the solenoid 42 and springs 53 and 53. That is, when the solenoid 42 is not energized, the link 51 supported by the shaft 52 is in a position where it is pulled by the spring 53 and rotated in the rotational direction of the lever 1, and is inserted into the elongated hole of the holding member 21. The brush material 10' held by the holding member 21 is at a position separated from the photoreceptor 1.

When the solenoid 42 is energized, the solenoid 42 moves the holding member toward the photoreceptor 1 through a series of links. That is, the link 44 supported by the shaft 45 is pulled via the link 43 and rotates counterclockwise. Link 44 further rotates links 47 and 49, which are respectively supported on shafts 48 and 50 via pin 46, counterclockwise and in the direction of the hour crystal 1, respectively. Links 47 and 49
is also engaged with links 51, 51- and connects them to the fifth
Rotate counterclockwise as shown in the figure. Link 51.51-
is engaged with the holding member 21 through an elongated hole provided therein, and is moved toward the photoreceptor.

Next, the drive mechanism for longitudinal linear movement of the holding member 21 will be described. The motor 30 rotates an eccentric disc cam 33 integrated with the worm wheel 32 via a worm 31 and a worm wheel 32. The link 35, which is supported by the guides 36 and 36- in a reciprocating manner, is pulled by a spring 41 hung between the guide 36- and the bottle 37 fixed to the link 35, and the roller 34 which is pivoted to the link 35 is brought into pressure contact with the cam 33 and reciprocates as the cam 33 rotates. A roller 39 attached to a shaft 38 hanging from one end of the link 35 linearly reciprocates the holding member 21 and hence the brush material 10 in the longitudinal direction via a U-shaped member 40 fixed to the holding member 21. In this way, the brush material is brought into contact with and released from the photoreceptor by the operation of the solenoid 42, and linear reciprocating movement in the longitudinal direction is performed by the operation of the motor 30.

Although the present embodiment is configured as described above, the invention is not limited to this and various modifications are possible.

For example, in the UA method of the disturbance means, in addition to the linear movement in the longitudinal direction of this embodiment, it is possible to move back and forth, and move up and down.

[Effects of the Invention] As explained above, in the cleaning device of the present invention, the brush that moves in the wedge-shaped space between the cleaning blade and the photoreceptor disturbs and removes the accumulated toner, thereby stabilizing the repetition of the copying process. Toner accumulation at the cleaning point that has an adverse effect on performance is removed, toner filming and paper dust are prevented from entering, and the life of the cleaning blade as a consumable item is extended and damage to the photoreceptor is reduced.

Further, as an effect of toner removal by the brush, the vicinity of the edge contact portion of the cleaning blade is also cleaned at the same time, which is highly effective in improving and maintaining cleaning performance.

Furthermore, in the case of the present embodiment in which the cleaning blade is released from the pressure bond, there is no need to provide a second toner collecting means, resulting in a compact and inexpensive device configuration, and the load on the mechanical drive is also reduced.

In this way, the present invention provides a cleaning device that can obtain high quality images over a long period of time using the conventional blade cleaning method that is easy to use, has high stability, and has good cleaning efficiency.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a sectional view showing the main parts of a color copying machine to which the present invention is applied, and FIG. 2 is an enlarged sectional view showing the cleaning device 11 in FIG. 3 is a plan view showing the drive mechanism of the toner agitation brush support member in the cleaning device 11, FIG. 4 is a front view of the same, FIG. 5 is a sectional view taken along line AA in FIG. 4, and FIG. FIG. 7 is a sectional view showing a conventional cleaning device, and FIG. 8 is a sectional view showing an improved cleaning device 6 of the conventional technique. . 1... Photoreceptor, 2... Cleaning blade, 3...
... Toner collection roller, 4 ... Cleaning 11-ra, 5 ... Scraper, 6 ... Toner guide, 7 ...
・Screening 1-18... Charger, °9... Laser exposure, 10... Brush material, 11... Cleaning device,
12...Yellow toner developing device, 15...Paper feeding device, 16...Transfer device, 17...Separator, 18...
Fixing device, 19... shaft, 20... holding device, 21...
- Holding member, 22... casing. Applicant's agent Hiroshi Fujimoto Kocha I Eye No. 2 Zucha 5 Figure No. 6

Claims (1)

[Claims] In a photoconductor cleaning device having a cleaning blade formed in a drum shape and pressed against the circumferential surface of a rotating photoconductor, the cleaning blade is inserted into a wedge-shaped space formed by the cleaning blade and the photoconductor, and the cleaning blade and the photoconductor are inserted into a wedge-shaped space formed by the cleaning blade and the photoconductor. Both sides of the tip of a conductive brush, which is a toner stirring means that moves relative to the body, are cut to match the surface of the photoreceptor and the surface of the cleaning blade, and a voltage is applied to the conductive brush. Photoconductor cleaning device.