JPH06124056A - Cleaning device - Google Patents

Abstract

PURPOSE:To increase a cleaning effect by allowing a cleaning blade to be stable in contact with a photosensitive drum for a long period and cleaning it. CONSTITUTION:Step screws 7 are attached on the supporting surface 6a of a drum frame 6 having a guiding surface 6a, a half fixed blade attaching plate 3 is supported by a projection 4 so as to be moved in a height range set by the supporting surface 6a and the head 7a of the step screw 7 and the cleaning blade 2 is fixed on the blade attaching plate 3. While the photosensitive drum 1 is rotated, the cleaning blade 2 lifts up the blade attaching plate 3 by frictional force to increase contact pressure and when the rotation is stopped, slight contact is obtained.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As is well known, an electrostatic copying machine exposes an original image to an electrostatically charged photoconductor to form an electrostatic latent image, and the photoconductor on which the electrostatic latent image is formed. Toner (developer) on top
Is electrostatically attached to develop. An electrostatic voltage having a polarity opposite to that of the toner image is applied to the toner image on the photoconductor to transfer the toner image onto the recording paper, and the transferred image on the recording paper is heated and pressed to fix the image. The toner remains on the photoconductor after the toner image has been transferred, so it is cleaned by a cleaning device, and the static electricity charged on the photoconductor is removed by irradiating the surface of the photoconductor with light to remove it in the next copy cycle. Make it transferable.

If the toner remains on the photosensitive member, the image quality is deteriorated, so that the cleaning device is an important process element for the electrostatic copying apparatus. As a cleaning device, it is most important not to leave residual toner on the photoconductor, but it is also a requirement that the cleaning property does not change for a long period of time without damaging the photoconductor or mixing in foreign matter other than toner. It is one. As such a cleaning device, there is a method of using a fur plan that rotates at high speed or a method of using a web-shaped paper, but recently,
A blade cleaning device in which a cleaning blade is brought into contact with a photoconductor is generally used. Next, the structure of the electrostatic copying apparatus will be described.

FIG. 7 is a block diagram for explaining an example of an electrostatic copying apparatus having a cleaning device according to the present invention. An original image (not shown) on the base is illuminated by the copy lamp 22 from the back side. The reflected light is reflected by the first mirror 24,
An image is formed on the photoconductor drum 26 via an optical system including the second / third mirror unit 25, the fixed focus lens 45, and the fourth / 5th mirror unit 44. Photoconductor drum 26
Is uniformly electrostatically charged by the image charger 23 after the static electricity is removed by the static elimination lamp 21, and an electrostatic latent image is formed on the photosensitive drum 26 by forming an image through the optical system. .

The electrostatic latent image is magnetically attracted to the toner supplied from the developing cartridge 27 by an MG (magnet) roller 28 and developed on the photosensitive drum 26. The toner image on the photosensitive drum 26 is transferred onto the recording paper conveyed from the cassette 46 by the paper feed rollers 32 and 33. The transfer is performed by applying static electricity having a polarity opposite to that of the toner from the transfer charger 16. The recording paper on which the toner image has been transferred is separated from the photosensitive drum 26 by the peeling roller 37, heated and pressed by the fixing device including the lower heat roller 38 and the upper heat roller 40, and detected by the post-fixing paper output detection switch 21. And then issued.

Photosensitive drum 26 after the toner image is transferred
Since the toner image remains on the surface of the photosensitive drum 26, it is cleaned by the cleaning blade 47 that elastically contacts the photosensitive drum 26. The cleaning blade 47 is
A strip-shaped plate of polyurethane or the like, which is elastic and has wear resistance, is used and is fixed to the blade mounting plate 48 of the cleaning device 49. The separated toner is cleaned by the cleaning device 49.
Housed inside. The surface charge of the photoconductor drum 26 after the toner is cleaned is neutralized by the light irradiation from the discharge lamp 21 and waits for the next copy cycle. In addition,
The mounting of the cleaning blade 47 is performed as follows.

FIGS. 8 (a) and 8 (b) are views showing a mounting member for a conventional cleaning blade.
a, a stop angle 50 having a stop pin 50b ((a)
As shown in the drawing, the cleaning blade 47 is sandwiched between the blade mounting plates 48 and fixed with screws 51.

[0008]

As described above, the cleaning blade 47 is sandwiched between the blade mounting plates 48 by the stop angle 50, and is screwed by the screw 51 to be completely fixed. As a result, the cleaning blade 47 is always in contact with the photosensitive drum 26 at a constant pressure. Since the cleaning blade is not a completely elastic body, the cleaning blade 47 is deformed when left for a long time.
As a result, the contact pressure differs from the initial value, and problems such as defective cleaning occur. In addition, since it is completely fixed, it cannot be adjusted in the vertical direction, the amount of blade biting and the cleaning point cannot be adjusted, and variations in assembly accuracy and parts accuracy cannot be dealt with. For this reason, accuracy of parts is required, which affects the cost and the yield.

[0009]

The present invention has been made to solve the above-mentioned problems, and (1) transfers a toner image formed on a photosensitive drum onto a recording paper, and after transfer A cleaning device for removing the toner remaining on the photoconductor drum, the drum frame being fixed in the cleaning device at a distance in parallel with the photoconductor drum, and within a predetermined height from the surface of the drum frame. A blade mounting plate movably fixed to the drum frame surface and a rectangular flexible material, one long side of which is fixed to the blade mounting plate and the other long side is in contact with the photosensitive drum. And a cleaning blade that
(2) In (1) above, a plurality of protrusions formed on the surface of the blade mounting plate that faces the surface of the drum frame and the blade mounting plate, and the blade mounting plate mounted on the drum frame have a predetermined height. And (3) in (1), a plurality of protrusions are provided on the surface of the drum frame facing the surfaces of the drum frame and the blade mounting plate. A columnar body having a length corresponding to the moving height of the blade mounting plate is provided, and the blade mounting plate is locked by a screw head of a screw screwed to the end of the columnar body, and further, (4 ) In any one of the above (1) to (3), a plurality of pairs of columnar bodies having different heights capable of selecting a plurality of movable heights of the blade mounting plate are arranged on the drum frame, and Is before (5) In any one of (1) to (4), the blade mounting plate is rotatably fixed to the drum frame by penetrating through a circular hole formed in the blade mounting plate, and the blade mounting plate is movable in the photosensitive drum direction by rotation. Having an eccentric screw to be adjusted, further, (6) above (1)
In any one of (5) to (5), the blade mounting plate is arranged so as to be vertically movable within a predetermined height range with respect to the drum frame and vertically and axially movable with respect to the photosensitive drum shaft. It is a feature.

[0010]

The function of the cleaning blade is not fixed relative to the photosensitive drum, but is fixed to the blade mounting plate which is vertically movable on the drum frame by a predetermined height.
The blade mounting plate is supported by the protrusion on the drum frame, and when the photoconductor drum is rotating, it is lifted by frictional force to enhance the cleaning effect. Perform stable cleaning for a certain period.

[0011]

1 (a), 1 (b) and 1 (c) are views for explaining an example of a cleaning device according to the present invention.
The figure is an overall perspective view, the figure (b) is a view taken along the line BB of FIG. (A), and the figure (c) is a view taken along the line C-C of FIG.
Reference numeral 1 is a photosensitive drum, 2 is a cleaning blade, 3 is a blade mounting plate, 4 is a protrusion, 5 is a guide hole, 6 is a drum frame, (fixing member), and 7 is a step biz.

In the figure, the drum frame 6 is a short plate-like member having a support surface 6a, a support surface 6a on one long side of the support surface 6a, and a guide surface 6b inclined slightly downward. Are fixed in parallel with the photosensitive drum 1 at a distance. A plurality of step screws 7 are attached to the drum frame 6 so as to be spaced apart in the longitudinal direction.

The post-blade mounting plate 3 is also a short plate-shaped member and has a flat surface portion 3a and a fixing surface 3b for fixing the cleaning blade 2 which is inclined slightly downward to the flat surface portion 3a. Further, the flat surface portion 3a is provided with guide holes 5 of the same number as the step screws 7 for guiding the step screws 7 attached to the drum frame 6, and a plurality of projections 4 in the longitudinal direction. The blade mounting plate 3 is disposed on the drum frame 6 and is supported by the support surface 6a by the protrusion 4 so as to be movable between the support surface 6a and the head 7a of the step screw 7.

The cleaning blade 2 is an elastic member having a rectangular shape and made of a wear-resistant resin material such as polyurethane. The cleaning blade 2 holds the photosensitive drum 1 even if it contacts and slides on the photosensitive drum 1. It has the property of removing toner without damaging it. The cleaning blade 2 is
It is fixed to the fixing surface 3b of the blade mounting plate 3 with an adhesive or a screw.

2A and 2B are sectional views for explaining the operation of the cleaning device according to the present invention.
The figure shows the state of the cleaning blade when the photosensitive drum 1 is stopped, and the figure (b) shows the state of the cleaning blade. In the state where the photosensitive drum 1 is stopped (a), no force acts between the photosensitive drum 1 and the cleaning blade 2, so that the blade mounting plate 3 has the projection 4 and the guide surface 6a.
And the cleaning blade 2 is stopped in a state of slightly contacting with the photosensitive drum 1.

When the photoconductor drum 1 rotates in the direction of arrow R, due to the contact frictional resistance between the photoconductor drum 1 and the cleaning blade 2, the blade mounting plate 3 is moved in the direction of arrow P in the same direction as the direction of rotation of the photoconductor drum 1. A force acts to lift the protrusion 4 in the downward direction of the arrow with the fulcrum as a fulcrum, and the surface of the photosensitive drum 1 is cleaned. At this time, since the cleaning blade 2 is lifted by the friction between the cleaning blade 2 and the photosensitive drum 1, the pressure acting on the cleaning blade 2 is increased and effective cleaning is performed. When the photoconductor drum 1 stops, the blade mounting plate 3 naturally drops to be in the state shown in FIG.

3 (a) and 3 (b) are sectional views for explaining another embodiment of the cleaning device according to the present invention, in which 9 is a drum frame projection, 10 is a boss, and 11 is a boss.
The same reference numerals as in FIG. 1 are attached to the parts having the same function as in FIG.

The drum frame protrusion 9 and the columnar boss 10 having a height H are integrally molded with the drum frame 6, and are resin molded, for example. The boss 10 has a screw 1 in the center
A hole 10a for screwing 1 is provided. Boss 1
0 guides the guide hole 5 of the blade attachment plate 3, and attaches the blade attachment plate 3 with the screw 11 in a semi-fixed state while maintaining the height H. Therefore, the projection 4 attached to the blade attachment plate 3 of FIG. 1 is not necessary. The structure shown in FIG. 3 eliminates the need for the step screw 7 and enables cost reduction.

FIG. 4 is a diagram for explaining still another embodiment of the cleaning device according to the present invention.
Reference numeral 2 denotes an eccentric screw, which has the same reference numeral as in FIG.

The eccentric screw 12 shown in FIG. 4 has an eccentric shaft 0-
It is attached to the drum frame 6 having 0, and by rotating this eccentric screw 12 in the arrow R direction, the blade mounting plate 3 can be moved in the arrow ± X direction.
As a result, the cleaning blade 2 can be brought close to or away from the photoconductor drum 1 and the contact pressure of the cleaning blade 2 on the photoconductor drum 1 can be adjusted.

5 (a), (b), (c), and (d) are views for explaining still another embodiment of the cleaning device according to the present invention, and FIG. A view, (b) figure is a BB line diagram of (a) figure, (c) figure is a CC line diagram of (a) figure, (d) figure is an arrow of (a) figure. It is a view D-D diagram, and the mark which acts the same as FIG. 1 is attached with the same reference number as FIG.

The height of the adjusting boss 13 is Ha, and the boss 11
A plurality of them are arranged in pairs in the longitudinal direction of the drum frame 6 at a height different from the height H. By disposing the boss 11 and the adjusting boss 13 having different heights, the contact pressure between the cleaning blade 2 and the photosensitive drum 1 can be adjusted. The screw 11 for semi-fixing the blade mounting plate 3 for this purpose is the boss 11 or the adjustment boss 1.
It suffices to fix 3 to only one of them after adjusting the contact pressure, and in the figure, it is shown attached to the boss 11.

6 (a), 6 (b), 6 (c), 6 (d) and 6 (e) are views for explaining still another embodiment of the cleaning device of the present invention. The figure is an overall perspective view, the figure (b) is the arrow BB line in the figure (a), the figure (c) is the arrow CC line in the figure (a), and the figure (d) is the figure (a). View line D-D, (e)
Is a line E-E as viewed in the direction of the arrow (a), and the same acting marks as those in FIGS. 1 and 5 are denoted by the same reference numerals as those in FIG.

FIG. 6 shows the function of adjusting the height for semi-fixing the blade mounting plate 3 by integrally mounting the drum frame protrusion 9, the boss 10 and the adjusting boss 13 on the drum frame 6, and the eccentricity. And a state in which the screw 12 is attached and the screw 12 is movably adjusted to the photosensitive drum 1 side.

[0025]

As is clear from the above description, according to the present invention, (1) the cleaning blade 2 is fixed to the blade mounting plate 3 which is semi-fixed so as to be movable with respect to the drum frame 6 within a predetermined height range. Since the blade mounting plate 3 is brought into point contact with the drum frame by the protrusions 4, the cleaning blade 2 is slightly in contact with the photosensitive drum 1 when the photosensitive drum 1 is stopped. Cleaning blade 2 during rotation
Since it moves so that the contact pressure becomes high, it can be stably cleaned without being deformed for a long period of time, and the cleaning effect becomes good. (2) Since the drum frame protrusion 9 and the boss 11 are formed integrally with the drum frame 6 and the blade mounting plate 3 is semi-fixed, the cleaning device can be provided with the same effect as the above (1) at a lower cost. (3) Since the eccentric screw 12 is attached to the drum frame 6, the contact pressure of the cleaning blade 2 on the photosensitive drum 1 can be easily adjusted. (4) Since the height at which the blade mounting plate 3 is moved when the blade mounting plate 3 is semi-fixed to the drum frame 6 can be adjusted, the position of the cleaning blade 2 with respect to the photosensitive drum 1 can be easily adjusted. . (5) Since the blade mounting plate 3 is semi-fixed and the semi-fixed height can be adjusted to adjust the position in the direction of the photosensitive drum 1, it is possible to correct variations in component accuracy and assembly accuracy. In particular, the tip of the cleaning blade 2 with respect to the rotation center of the photosensitive drum 1 can be adjusted, which is advantageous. Further, the pressure of the cleaning blade 2 can be adjusted even during the life, and the life can be extended.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an example of a cleaning device according to the present invention.

FIG. 2 is a cross-sectional view for explaining the operation of the cleaning device according to the present invention.

FIG. 3 is a sectional view for explaining another embodiment of the cleaning device according to the present invention.

FIG. 4 is a diagram for explaining still another embodiment of the cleaning device according to the present invention.

FIG. 5 is a view for explaining still another embodiment of the cleaning device according to the present invention.

FIG. 6 is a view for explaining still another embodiment of the cleaning device according to the present invention.

FIG. 7 is a diagram illustrating an example of an electrostatic copying apparatus having a cleaning device according to the present invention.

FIG. 8 is a view showing a conventional mounting member for a cleaning blade.

[Explanation of symbols]

1 ... Photosensitive drum, 2 ... Cleaning blade, 3 ... Blade mounting plate, 4 ... Projection, 5 ... Guide, 6 ... Drum frame, (Fixing member), 7 ... Step beads, 9 ... Drum frame projection, 10 ... Boss , 11 ... Screw, 13 ... Adjustment boss.

Claims (6)

[Claims] 1. A cleaning device for transferring a toner image formed on a photoconductor drum onto a recording paper, and removing the toner remaining on the photoconductor drum after the transfer, a cleaning device for separating the toner image in parallel with the photoconductor drum. A drum frame fixed in the cleaning device, a blade mounting plate fixed to the drum frame surface so as to be movable within a predetermined height from the surface of the drum frame, and a rectangular flexible material, A cleaning device characterized in that one side of a long side is fixed to the blade mounting plate, and the other long side is a cleaning blade in contact with the photosensitive drum. 2. A plurality of protrusions formed on the surface of the blade mounting plate facing the surfaces of the drum frame and the blade mounting plate, and the blade mounting plate mounted on the drum frame are movable by a predetermined height. The cleaning device according to claim 1, further comprising a stepped screw for locking. 3. A plurality of protrusions and a columnar body having a length corresponding to the moving height of the blade mounting plate are provided on the surface of the drum frame facing the surface of the drum frame and the blade mounting plate. The cleaning device according to claim 1, wherein the blade mounting plate is locked by a screw head of a screw screwed to the end of the columnar body. 4. The drum frame is provided with a plurality of pairs of columnar bodies each having a different height from which a plurality of movable heights of the blade mounting plate can be selected.
The cleaning device according to any one of items 1 to 3. 5. An eccentric screw that rotatably adheres to the drum frame through a circular hole formed in the blade mounting plate and that adjusts the blade mounting plate movably in the photosensitive drum direction by rotation. The cleaning device according to any one of claims 1 to 4, wherein: 6. The blade mounting plate is arranged so as to be movable in the vertical direction with respect to the drum frame within a predetermined height range and to be movable in the vertical direction and the axial direction with respect to the photosensitive drum shaft. Item 6. The cleaning device according to any one of Items 1 to 5.