JPH01164987A - Cleaning device for photosensitive body - Google Patents

Abstract

PURPOSE:To main cleaning performance at a high level extending over a long period by cutting the one side plane of the tip of a conductive brush that is a toner stirring means fitting in the plane of a photosensitive body, and impressing a voltage on the conductive brush. CONSTITUTION:The tip part of the conductive brush 10 is cut fitting in the surface of the photosensitive body, and the brush is brought into contact with the photosensitive body at the tip part elastically, and also, an AC voltage is applied. Therefore, a toner scraped from the surface of the photosensitive body 1 by a cleaning blade 2 is stirred mechanically by the brush 10, and also, the voltage is applied, and an attractive force by an electrostatic force is eliminated, then, drops, thereby, no toner is accumulated at a wedge shape part formed between the photosensitive body 1 and the cleaning blade 2. Thereby, no toner remains on the cleaning blade 2 at the time of separating the cleaning blade 2 from the photosensitive body 1, and also, no toner is attached on the blade for the long period. In such a way, the cleaning performance can be stabilized and maintained at the high level.

Description

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

[Prior Art] Conventionally, as a means for cleaning transferred toner from an image forming body of an electrophotographic apparatus, that is, a photoreceptor, a blade cleaning method, which has a simple structure and has high cleaning efficiency, has been used. 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 row.

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 any dirt remaining on the surface. When toner images in the process of being formed (first color toner images, second color toner@, etc.) pass, these toner images must not be disturbed, so they are retracted to a position t indicated by a solid line.

During cleaning, the toner scraped off by the cleaning blade 2 falls downward and is collected by the toner collection row 53 located below toward the toner reservoir.

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 dark 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 retreats. Due to this condition, cleaning defects may occur where the particles pass through the cleaning device without being scraped off.

In this way, the toner that has not reached ff1hs moves with the rotation of the photoconductor 1 and is diffused to other parts of the photoconductor surface, or is scattered, and the toner is scattered around the photoconductor 1, such as the band Ti device and the developing device. This may stain peripheral equipment such as containers, transfer devices, and separators, thereby hindering the formation of high-quality images.

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 residual toner that has passed through the cleaning blade 2 by wiping it off. Of course, like the cleaning blade 2, this cleaning roller 4 is also
It is designed to retreat when a toner image that is in the process of being formed passes through. The toner that has been wiped off by the cleaning roller 4 and deposited on its surface is scraped off by the scraper 5.

Since the cleaning row 54 is provided for the above purpose, after the cleaning blade 2 is retracted, it comes into contact with the photoreceptor 1 before the accumulated toner adhering to the photoreceptor 1 arrives, and the cleaning blade 2 is retracted. At this time, the contact state continues until the part of the photoreceptor 1 facing the toner collection roller 3 passes the cleaning roller 4, and then retreats.

Cleaning roller 4 in an actual image forming apparatus,
Considering the spacing between the cleaning blade 2 and the toner collection roller 3 and the circumferential distance of the photoreceptor 1, the cleaning roller 4 will move onto the photoreceptor 1 immediately after the cleaning blade 2 is retracted.
and will be evacuated in a short period of time.

[Dark problem to be solved by the invention] The cleaning device explained above (Patent Application No. 6O-2330
No. 19) is effective in effectively cleaning up the accumulated toner adhering to the photoreceptor when the cleaning blade is retracted.

However, in addition to the toner recovery device from the toner recovery roller, the equipment becomes complicated because it requires a toner recovery device from the cleaning roller, and space is required to arrange the cleaning roller downstream of the cleaning blade. Furthermore, 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 body.

The present invention has been made in order to solve the above-mentioned problems.The present invention has been made in order to improve the cleaning performance, which is the main function for cleaning toner, in a photoconductor cleaning device having a drum-shaped cleaning blade that is pressed against the circular surface of a rotating photoconductor. It is an object of the present invention to provide a cleaning device for a compact image forming apparatus, which can maintain high quality images for a long period of time, prevent staining of various devices installed around an image forming body, and form high quality images for a long period of time. .

[First Step to Solve 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. One side of the tip of a conductive brush, which is a toner stirring means that is inserted into a model space formed by a cleaning blade and a photoreceptor and moves relative to the cleaning blade and the photoreceptor, is cut to match the surface of the photoreceptor. It is characterized in that 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 gutter remains on the photoreceptor or on the cleaning blade, and the area around the image forming member is not contaminated. Further, since the toner bar 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 produced for a long period of time. In particular, the conductive brush, which is the toner agitating means of the present invention, has a tip cut to match the surface of the photoreceptor, so that the brush contacts the photoreceptor with the tip of the bristles, resulting in high toner removal performance.

[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 laser light 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 charging exposure and development described above is repeated once for each color, thus three times for three colors. The above laser exposure is main-scanned in the direction perpendicular to the plane of the paper and is combined with sub-scanning by drum rotation to form N latent images corresponding to yellow, magenta, and cyan images on the surface of the photoreceptor, but the laser exposure is modulated. 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 photoreceptor 1. To explain the time course, during the first rotation of the photoreceptor 1, the charged latent image corresponding to the yellow toner created by the laser exposure 9 becomes yellow. Toner developing device 12
By applying a direct current to the toner, the image is developed by the developing roller 12-, and an image of the Y0-toner is formed on the surface of the photoreceptor 1. Similarly, during the second rotation of the photoconductor 1, the photoconductor 1 is
Magenta toner is deposited on the surface of the image. Also, the photoreceptor 3
The developing roller 14 of the cyan toner developing device 14 is located at the rotation point.
′ causes cyan toner to adhere.

The color image thus formed on the surface of the photoreceptor is transferred by the transfer device 16 onto the recording paper fed by the paper feeder 15J. 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 cleaning device 11 first coats the photoreceptor with yellow toner +
It passes with the IIS image on it, and then it passes with the yellow toner and magenta toner images on it. When the untransferred image passes like this, the cleaning device 1
1 is deactivated, and the cleaning device 11 is activated only at other times. The cleaning device will be explained below with reference to FIG. 2 is a cleaning blade constituting the main cleaning means; shaft 1
The photoreceptor 1 is held by a holding device 20 that is driven to rotate around 9, and is brought into and out of pressure contact with the photoreceptor 1 .

Reference numeral 10 denotes a conductive brush material serving as toner agitating means, which 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 the surface of the photoreceptor and retracted. Driving is also performed. As shown in FIG. 6, the conductive brush material 10 has a tip cut to match the surface of the photoreceptor, and the brush contacts the photoreceptor elastically at the tip. Further, the conductive brush material 10 is configured so that an alternating current voltage of 500 to 700 cm is applied thereto.

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

3, the toner receiver is arranged with a gap of about 0.2 to 0.3M between the toner collecting row and the photoreceptor 1, and is rotated in the direction of the arrow, and is driven by a positive DC voltage. Approximately 500 V is applied. Reference numeral 6 is a gutter guide that carries the toner from above the toner collection roller 3 to the lower groove of the casing 22. Reference numeral 7 is a groove guide that collects the toner from the top of the toner collection roller 3 to the lower groove of the casing 22. As the screw rotates, a spiral blade 7 collects the toner into a toner reservoir. send to.

Next, the operation of the cleaning device will be explained. As mentioned above, the cleaning device does not operate when an untransferred tonneau image passes, so the cleaning blade 2 is held at a position separated from the photoreceptor 1. 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 as long as the imaged portion passes through. 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 a voltage of opposite polarity to the toner is applied to the toner recovery [1-ra 3], 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 the water device, the cleaning blade is cleaned from the photoreceptor after the transferred residual toner has passed, but at that time, the toner that had accumulated between the cleaning blade and the photoreceptor remains on the photoreceptor. In order to prevent the blade from leaving the photoreceptor, the conductive brush material 10 enters toward the toner retention area at the point where the blade leaves the photoreceptor, and combines the mechanical peeling force due to the toner disturbance operation of the linear movement 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 may 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 the brush may be withdrawn for a time that does not affect the leading edge of the toner image in the next copying process. It doesn't matter what time it is, as long as it's within. Also, the voltage application can be turned on and off according to the process.

That is, a voltage is applied when the conductive brush is inserted toward the tonneau-n clasp, 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.

Carbon is the best brush material! Particularly suitable are fibers, conductive acrylic fibers, conductive rayon, conductive polyester, and the like having a resistance value of about 10<-3> to 10<10 >[Omega].alpha.

Next, the drive mechanism of the holding member 21 of the brush material 10 will be explained with reference to FIG. 3 to FIG. 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 movement of the holding member 21 forward and backward toward the photoreceptor 1 is performed by the action of the solenoid 42 and springs 53, 53. That is, when the solenoid 42 is not energized, the link 51 supported by the shaft 52 is pulled by the spring 53 and rotated in the clockwise direction, and is inserted into the elongated hole of the holding member 21. The portion shown in FIG. 1 is located at a position moved to the left, and therefore, the brush material 10 held by the holding member 21 is located 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. Meanwhile, the link 44 supported by the shaft 45 is pulled through the link 43 and rotates counterclockwise. Link 44 further rotates links 47 and 49, which are supported on shafts 48 and 50, respectively, via pin 46, counterclockwise and clockwise, respectively. Links 47 and 49 also engage links 51 and '51 = to rotate them in the counterclockwise direction shown in FIG. Link 51.
51- engages with the holding member 21 through a long hole provided therein, and moves it toward the photoreceptor.

Next, a driving mechanism for linear movement of the holding member 21 in the longitudinal direction 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 pin 37 fixed to the link 35, and the roller 34 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 reciprocation in the longitudinal direction is performed by the operation of the septa 30.

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

For example, as for the method of driving the disturbance means, in addition to the linear movement in the longitudinal direction of this embodiment, back-and-forth movement, vertical movement, etc. are possible.

[Effects of the Invention] As explained above, in the cleaning device of the present invention, the brush that moves in the pattern between the cleaning blade and the photoreceptor disturbs and removes the accumulated toner, thereby improving the copying process. Toner accumulation at cleaning points that adversely affects repeat stability is removed, toner filming and paper powder contamination are prevented, 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 can replace the conventional simple and stable epidemic.
To provide a cleaning 5A device capable of obtaining high quality images over a long period of time using a blade cleaning method with high cleaning efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of a color copying machine to which the present invention is applied, FIG. 2 is an enlarged sectional view showing the cleaning device 11 in FIG. 1 excluding the drive section, and FIG. A plan view showing the drive mechanism for the toner disturbance brush support member in the cleaning device 11, FIG. 4 is a front view of the same, and FIG.
The figure is a Δ-Alei side view in Fig. 4, Fig. 6 is an enlarged view of the conductive brush used in the present invention, Fig. 7 is a sectional view showing a conventional cleaning 5A position, and Fig. 8 is an improved one. FIG. 2 is a sectional view showing a conventional cleaning device according to the prior art. 1... Photoreceptor, 2... Cleaning blade, 3...
... Toner collection roller, 4 ... Cleaning roller,
5... Scraper, 6... Toner guide, 7...
Screw, 8... Charger, 9... Laser exposure, 1
0 River brush material, 11...Cleaning device, 12...
・Ye0-toner developing device, 15...paper feeding device, 16
...Transfer device, 17...Separator, 18...Fixer,
19... Shaft, 20... Holding device, 21... Holding member, 22... Casing. Applicant's agent Hiroshi Fujiki Mitsushiba 7g 28th 5th drawing 6th

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. A photoreceptor cleaning device characterized in that one side of the tip of a conductive brush, which is toner stirring means that moves relative to the body, is cut to match the surface of the photoreceptor, and a voltage is applied to the conductive brush. .