JPH01137281A - Cleaning device for photosensitive body - Google Patents

Abstract

PURPOSE:To eliminate a toner bank, paper powder, etc., by inserting a conductive brush into a wedge-shaped space part formed by a cleaning blade and a photosensitive body and bringing this brush to relative motion against the cleaning blade and the photosensitive body. CONSTITUTION:A cleaning blade 2 is separated from a photosensitive body 1, after the transferred remaining toner has passed through, but in that case, a conductive brush materials 10 goes into this toner remaining part before the blade 2 is separated from the photosensitive body, so that the toner which has collected between the blade and the photosensitive body 1 does not remain behind on the photosensitive body, a holdup toner is stirred up and eliminated by a composite effect of mechanical peeling force by a toner stirring-up operation of a linear movement operation and electric force of an AC voltage, and the toner is eliminated almost completely from the surface of the photosensitive body and the reverse side of the cleaning blade. The eliminated toner drops down on a toner collecting roller 3 and fed to a toner guide 6 and collected. In such a way, toner filming and mixing of paper powder, etc., are prevented.

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 toner after transfer from an image forming body, that is, a photoreceptor, of an electrophotographic apparatus, 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 roller.

When cleaning, the cleaning blade 2 advances to the right in the figure and brings the end corner into contact with the surface of the photoreceptor 1 as shown by the dotted line to scrape off the toner remaining on the surface and clean it. When the toner images (first color toner image, second color toner image, etc.) pass, these toner images must not be disturbed, so they are retracted to the position shown 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 is being written down and falling by the cleaning blade 2 often adheres to the surface of the photoconductor 1 between the position where the cleaning blade 2 was in contact and the position facing the toner collection roller, and the cleaning blade 2
Since the particles are in a retracted state, this may cause a cleaning failure in which the particles pass through the cleaning device without being scraped off.

The toner that could not be completely cleaned moves as the photoconductor 1 rotates and spreads or scatters to other parts of the photoconductor surface, causing the charger disposed around the photoconductor 1, the current II. This may stain peripheral equipment such as the printer, transfer device, and divider, thereby hindering the formation of high-quality images.

Therefore, the inventors of the present invention have invented a means to clean the toner that has been removed without being scraped off by the cleaning blade 2 during the retracting operation of the cleaning blade 2.
The applicant is currently applying for a patent. (Special application 1986-
233019) 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 (the movement at the contact portion is in opposite directions),
Clean the cleaning blade 2 by wiping off the remaining toner. Of course, like the cleaning blade 2, this cleaning roller 4 is also retracted when a toner image that is being formed passes therethrough. Toner that has been wiped off by the cleaning row 54 and adhered to its surface is scraped off by the scraper 5.

The cleaning roller 4 is provided for the above purpose, so that 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 portion of the photoreceptor 1 facing the toner collection roller 3 passes the cleaning roller 4, and then the toner collection roller 3 is moved back and forth.

Cleaning roller 4 in an actual image forming apparatus,
Considering the spacing between the cleaning blade 2 and the 1-ner recovery roller 3 and the circumferential distance of the photoconductor 1, the cleaning roller 4 comes into contact with the photoconductor 1 immediately after the cleaning blade 2 retreats, and is evacuated in a short time. .

[Problem to be solved by the invention 1 Patent application No. 6O-233 for placing the above-described cleaning row
No. 019) has achieved results by thoroughly cleaning the dirt and debris that adhered to the photoreceptor when the cleaning blade was retracted.

However, in addition to the gutter collection device from the toner collection roller, the mechanism becomes complicated due to the provision of a toner collection device from the cleaning roller, and the need for space 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 member.

The present invention has been made to solve the above-mentioned problems, and is used in a photoconductor cleaning device having a cleaning blade formed in a drum shape and pressed against the circular surface of a rotating photoconductor. To provide a cleaning device for a compact image forming apparatus that maintains high cleaning performance over a long period of time, prevents staining of various devices installed around an image forming body, forms high quality images over a long period of time, and is compact. With the goal.

[Means for Solving the Problems] In a photoconductor cleaning device that has a cleaning blade that is formed in a drum shape and presses against the same surface of a rotating photoconductor, a pattern formed by the cleaning blade and the photoconductor is provided. A conductive brush serving as toner agitation means is inserted into the space, and is moved relative to the cleaning blade and the photoreceptor while a voltage is applied thereto.

[Function] The toner scraped off from the surface of the photoreceptor by the cleaning blade is mechanically disturbed by the toner agitation means and a voltage is applied to remove the adhesion force due to electrostatic force and cause it to fall, so that the contact between the photoreceptor and the cleaning blade is No dirt accumulates on the model part.

Therefore, when the cleaning blade is separated from the photoreceptor, no toner remains on the photoreceptor or on the cleaning blade, and the area around the image forming member is not contaminated. In addition, since 1-ner does not adhere to the cleaning blade for a long period of time, the cleaning performance remains stable and high, ensuring good performance for a long period of time! 1 image can be obtained.

[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) formed by FH on a cylindrical LF body 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. The toner' is transferred to the developing device 12 (13, II
). 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 paper surface 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 dove created by the laser exposure 9 is formed. By applying a direct current to the yellow toner developing device 12, the yA image roller 1
2' to form a yellow toner image on the surface of the photoreceptor 1. During the second rotation of the photoreceptor 1, magenta toner is similarly applied to the surface of the photoreceptor 1 by the developing roller 13- of the magenta toner developing device 13. Further, during the third rotation of the photoreceptor, cyan and boolean is deposited by the developing roller 14'' of the cyan toner developing device 14.

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 images are 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 way, when an untransferred image passes, the cleaning device 11 is deactivated, and the cleaning device a11 is activated at other times. The cleaning device will be explained below with reference to FIG. 2 is the Lord! With the cleaning blade that constitutes the cleaning means @19
The photoreceptor 1 is held by a holding device 20 that is rotationally driven.
The pressure contact is made and the pressure contact is released.

10 is a toner-disturbing means) g An electric brush material is held by a holding member 21, and the holding member 21 is driven so as to make a linear movement in the depth direction of the apparatus, and also moves against the surface of the photoreceptor. Pressing and retracting drive is also performed. Also 31f
The structure is such that an AC voltage of 500 to 700 cm is applied to the fi-sensitive brush material 10.

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

3 is a toner collecting roller that constitutes a member, and is arranged with a gap (0) of about 0.2 to 0.3 m between it and the photoreceptor 1, and is driven to rotate in the direction of the arrow, and is supplied with a positive DC voltage. Approximately 500 μ is applied. Reference numeral 6 denotes a toner guide that transports toner from above the tonneau collection roller 3 to the casing 22.
lead to the lower groove. 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 image forming 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 collection 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 groove collection roller rotates.

Next, in this device, the cleaning blade is separated from the photoconductor after the transferred residual toner passes through it, but at that time, the toner that has 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, and the mechanical peeling force due to the groove disturbance operation of the linear motion and the alternating current voltage are applied. The combined effect with the electric force disturbs the staying toner and almost completely removes the toner from the surface of the photoreceptor and the center 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. When the brush is inserted into the wedge-shaped space between the cleaning blade and the photoreceptor,
It can be done at any time after the blade is pressed into contact with the blade, and at any time when the blade is retracted as long as it does not affect the leading edge of the toner image in the next copying process.
I can't help it. In addition, voltage application can be switched on and off according to the process.

That is, 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 it is also possible to use a combination of direct current and alternating current.

As the brush material, carbon fibers, acrylic fibers from ¥J Dentake, conductive rayon, conductive polyester, and the like having a resistance value of about 10<-4> to 10<5 >[Omega].alpha. are particularly suitable for use.

Next, the drive mechanism of the holding member 21 of the brush material 10 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 pulled by the spring 53 and is in a rotated position in the rotational direction of 31, and is inserted into the elongated hole of the holding member 21. This portion 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. That is, the links 4 supported by the shaft 45 are pulled via the link 43 and rotated 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. Link 47 Onibi 49
is also engaged with links 51, 51- and connects them to the fifth
Rotate it in the opposite direction 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' so as to be able to reciprocate, is pulled by a spring 41 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 in pressure contact with the cam 33, and the knob 33
As it rotates, it reciprocates f) J. A roller 39 attached to a shaft 38 hanging from one end of the link 35 is attached to the holding member 21.
The holding member 21 and therefore the brush material 10 are linearly reciprocated in the longitudinal direction via the U''/' shaped member 40 fixed to the U''/' shaped member 40. In this way, the contact and release of the brush material with the photoreceptor is controlled by the solenoid 42. The linear reciprocation in the longitudinal direction is effected by the actuation of the motor 31.

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 force direction of the hand in this embodiment, back-and-forth movement, vertical movement, or rotational movement on a cross section perpendicular to the axis of the photoreceptor is possible.

In addition, the disturbance means may be a brush with bristles planted in a straight line as shown in FIG. 6(a) of this embodiment, or a brush with bristles planted in a step shape as shown in FIG. 6(b). Figure 6 (C)
A brush with intermittent bristles as shown in Figure 6(d), a curly stem type with wavy bristles as shown in Figure 6(d), or a loop-shaped brush as shown in Figure 6(e). A brush can also be used. Furthermore, as shown in Figure 6(f), there is a method in which a belt stretched between two boots is coated with hair and the belt is rotated, and as shown in Figure 6(9), magnetic particles are coated with hair on a magnet. It is also possible to use a magnetic brush held upright.

[Effects of the Invention] As explained above, in the cleaning device of the present invention, the brush moving in the patterned space between the cleaning blade and the photoreceptor disturbs and removes the accumulated toner, so that the copying process is repeated. Toner accumulation at the cleaning point, which has a negative effect on stability, is removed, toner filming and paper powder contamination are prevented, the life of the cleaning blade as a consumable item is extended, and damage to the photoreceptor (n) is reduced. It will be done.

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 has a great effect on improving and maintaining cleaning performance.

Furthermore, in the case of the present example 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 a conventional blade cleaning method that is simple, highly stable, and has good 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. 4 is a front view of the driving mechanism of the toner disturbance brush support member in the cleaning device 11, FIG. 5 is a sectional view taken along line A-A in FIG. 4, and FIG. 7 is a sectional view showing a conventional cleaning device, and FIG. 8 is a sectional view showing an improved conventional cleaning device. 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...Brush material, 11...Cleaning device, 12
...Yellow toner current device, 15...Paper feeding device,
DESCRIPTION OF SYMBOLS 16... Transfer device, 17... Separator, 18... Fixing device, 19... Shaft, 20... Holding device, 21... Holding member, 22... Casing. Applicant's agent Hiroshi Fujimoto Mitsushiba 7g Figure 2 Figure 5 Figure Ca) <c>

Claims (1)

[Scope of Claims] 1. 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, a wedge-shaped space formed by the cleaning blade and the photoconductor is provided. A photoconductor cleaning device comprising: a conductive brush that is inserted and is a toner stirring means that moves relative to the cleaning blade and the photoconductor; and a power source that applies voltage to the conductive brush. 2. The photoconductor cleaning device according to claim 1, wherein the application of the voltage is controlled according to the photoconductor cleaning process.