JPS6337388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the invention (industrial application field) The present invention relates to a cleaning device for removing residual developer from an image bearing member, and particularly to a cleaning device using an elastic cleaning blade. It is.

(Prior art and issues to be solved) Conventionally, based on electrophotography, an electrostatic latent image is formed on a photoreceptor having a photoconductive layer, developed directly on the photoreceptor, and after using the developer, the photoreceptor is 2. Description of the Related Art It is widely practiced to clean and reuse image carriers such as bodies.

For this type of cleaning, methods such as the fur brush method, web method, and blade method have been proposed, but the blade method is particularly used as a practical method, and the last blade method is particularly popular due to its high cleaning efficiency and compactness of the device. It is commonly used.

By the way, it is desirable to prevent the developer scraped off by the cleaning blade from escaping to the outside when the cleaning blade is separated from the image carrier when inactive. Furthermore, when the cleaning device is taken out for maintenance, repair, etc., it is desirable to protect the tip of the cleaning blade.

The present invention aims to provide a device that satisfies the above two requirements with a simple configuration.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, the present invention provides a cleaning device that removes developer remaining on the image bearing member, which makes contact with the image bearing member. an elastic cleaning blade that removes developer on the image carrier; and a movable movable blade that supports the elastic cleaning blade so that it can take an operating position in which it contacts the image carrier and a retracted position in which it is retracted from the operating position. a first supporting means; a shutter/developer scooping member for preventing scattering of the developer removed from the image carrier by the elastic cleaning blade; an operating position on the upstream side that faces the elastic cleaning blade and contacts the image carrier to scoop up the developer removed by the elastic cleaning blade; and a closed state in which the elastic cleaning blade is retracted from the operating position. movable second support means for supporting the elastic cleaning blade so that it can assume a closed position; and the second support means is moved in conjunction with the movement of the first support means, so that the elastic cleaning blade is separated from the operating position. and an actuating means for inserting the tip of the shutter/developer scooping member into the gap formed between the image carrier and the elastic cleaning blade to close the gap and prevent the developer from scattering. It is something.

In this way, since the tip of the shutter/developer scooping member is inserted into the gap between the image carrier and the elastic cleaning blade that is created when the elastic cleaning blade is separated from the operating position, it is possible to use one member. This makes it possible to dissipate the developer and protect the tip of the cleaning blade.

(Explanation of Examples) The details of the present invention will be explained below using specific examples.

FIG. 1 is a perspective view showing an example of the arrangement of the present invention.
The image carrier 1 has a photoreceptor 2 supported in the form of a drum, and rotates in the direction of the arrow. A cleaning device 3 is disposed substantially near the top of the image carrier 1, ie, against the upward facing surface of the photoreceptor.

The cleaning device 3 includes an elastic cleaning blade 31 that contacts the surface of the photoreceptor, a shutter/developer scooping member 19, a conveying screw 33, and the like.

The elastic cleaning blade 31 is supported by a blade holder 7 which is swingably supported by a support shaft 22, and the shutter/developer scooping member 19 is supported by a connecting pin 18-1, which will be described later, so as to be able to move toward and away from the blade. ing.

The developer removed by the elastic cleaning blade 31 is transported laterally by a transport screw 33 and falls into a duct 9 disposed at the side end of the image carrier. The duct 9 is connected to a developer storage tank 10 of the developing device 10.
₁ , allowing the removed developer to be reused. By the way, it goes without saying that this duct may not only connect the cleaning section and the developing section in a substantially straight line as in the conventional system shown in the figure, but may also be constructed as a passage having a curved point of inflection.

FIG. 2 is a perspective view illustrating an operating mechanism for operating the elastic cleaning blade 31 and the shutter/developer scooping member 19 of an embodiment of the apparatus according to the present invention. Note that the directions in each operation explanation in the following explanation are based on the case from the viewing direction of Figure A.

The elastic cleaning blade 31 is attached to the image carrier 1.
An operating lever 21 is attached to a blade support shaft 22 serving as a first support means that supports the blade so as to be movable toward and away from the blade. A pressure knob 11 is provided at the end of the operating lever 21 opposite to the end at which the blade support shaft 22 is attached. The pressure knob 11 is integrally formed with a shaft 11-1 that passes through the end of the operating lever and rotates. A coil spring 29 is arranged on the shaft 11-1,
When the pressure knob 11 is rotated clockwise, a force is always applied to return it counterclockwise. A pressure lever 12 is fixed to the end of the shaft 11-1 opposite to the pressure knob 11. Axis 11-1
An engagement pin 13 is fixed to approximately the tip of the pressure lever 12 which rotates around the center, and a stationary position regulating pin 14 (described later) is fixed to approximately the center of the pressure lever.

Free lever 15 with a long hole 15-1 formed at the end
is engaged with the engagement pin 13 of the pressure lever 12 at the end opposite to the end with the elongated hole.

On the other hand, a shutter lever 16 is fixed to substantially the shaft end of a shutter support shaft 17 for swinging the shutter/developer scooping member 19, and controls the rotation of the support shaft 17. An engagement pin 16-1 is fixed to the opposite end of the shutter lever 16 fixed to the support shaft 17, and this engagement pin 16-1 fits into the elongated hole 15-1 of the free lever 15. ing. Also, a shutter stopper member 2 that engages with the tip of the engagement pin 16-1 and restricts the counterclockwise rotation of the shutter lever when the operating lever 21 swings.
4 is fixed to the operating lever 21.

Further, a support lever 18 as a second support means for swingably supporting the shutter/developer scooping member 19 is fixed to the shutter support shaft 17, and the shutter/developer scooping member 19 is attached to the opposite end.
The engagement pin 18-1 with 9 is fixed. The support lever 18 is always given a counterclockwise rotational force.

FIG. 2 shows that the elastic cleaning blade 31 is separated from the image carrier and housed in the cleaning device.
The shutter/developer scooping member 19 is about to be unclosed from the closed state.

When the pressure knob 11 of the operating lever 21 is manually rotated clockwise against its counterclockwise elastic return force, the pressure lever 12 also rotates.
Due to this rotation, the free lever 15 also rotates in the same direction, but the shutter lever 1 is engaged with the engagement pin 16-1 through the long hole 15-1 on the lever.
9 is also moved in the same direction. According to this movement of the shutter lever 16, the shutter support shaft 17
rotates, causing the support lever 18 to rotate clockwise.

The shutter/developer scoop member 19 moves upward in the direction of the arrow shown in the figure as the support lever 18 rotates, and the shutter/developer scoop member 19, which covers the tip of the elastic cleaning blade 31 at a position not shown, The edge of member 19 separates from the tip.

On the other hand, the stop position regulating pin 14 of the pressure lever 12
In the closed state of the shutter/developer scooping member 19, the locking groove 20-1 provided in the locking plate 20
However, as the pressure lever 12 rotates, it moves out of the locking groove 20-1. As the stop position regulating pin 14 moves, the safety lever 26 rotates counterclockwise and stops at the stopper 20-2. One end thereof is positioned so as to cover the mounting screw 28, and prevents the mounting screw from being removed when the shutter is in the open state.

When the stop position regulating pin 14 comes out of the locking groove, the operating lever 21 can be swung. Therefore, the pressure knob 11 is manually pushed downward, the operating lever 21 is rotated counterclockwise, and the blade support shaft 22 is rotated counterclockwise, thereby moving the elastic cleaning blade 31 to the pressure contact position.

In this process, the pressure knob 11 is
It returns to its original position by the biasing force 9, and the restraining force exerted on the shutter lever 16 by the free lever 15 is released. However, since the engagement pin 16-1 of the shutter lever 16 engages with the shutter stopper member 24 provided on the operating lever 21, the shutter/developer scooping member 19 remains open. In addition, the above-mentioned shutter stopper member 2
4, the shutter member has an arcuate edge centered on the blade support shaft 22, and the shutter member is always brought within a certain distance from the cleaning blade 31 while the operating lever 21 is rotating. I try not to. Then, the shutter member is regulated to a position where it can suitably perform the function of the scoop member which also serves as the shutter member.

The operating lever 21 that has been rotated to the cleaning position is fixed by being engaged with the stop position regulating pin 14 in an engagement groove (not shown).

In this state, the elastic cleaning blade 31 comes into contact with the image carrier with appropriate pressure, while the edge of the shutter/developer scooping member 19 maintains a predetermined distance from the tip of the cleaning blade 31. The cleaning blade 31 is installed at a suitable position where the tip of the cleaning blade 31 can effectively scoop up the developer removed.

Although the edge of the shutter/developer scooping member 19 may come into contact with the image carrier, since it is supported in a swingable manner, there is no risk of overloading the surface of the image carrier. There is no risk of scratches or wear.

The above operating mechanism may be released in the reverse order of the above operations.

What is important in the above mechanism is the torsional moment based on the coil spring 29 of the pressure lever 12.
The purpose is to maintain a relationship between M _p and the torsional moment M _s based on the coil spring 27 of the safety lever 26 so that M _p is sufficiently larger than M _s . By satisfying this condition, the stationary position regulating pin 14 can be attached to the locking groove.
The shutter can be kept stationary and the closed state of the shutter can be maintained well. In this state, the mounting screws can be freely attached and detached.

In addition, when the shutter is closed, the stationary position regulating pin 14 is stationary in the locking groove, so the operating lever 21 cannot be rotated as described above, and therefore the operation of the elastic cleaning blade 31 is completely blocked. There is.

On the other hand, when swinging the operating lever 21,
Since the shutter/developer scooping member 19 has already been opened and held in a position where it does not interfere with the movement of the cleaning plate 31, it is clear that there is no risk of the two colliding and causing damage or other accidents.

FIG. 3 is a plan view of the operating mechanism shown in FIG. 2 and its surroundings of the apparatus according to the embodiment of the present invention, as viewed from the image carrier side.

As described above, the coil spring 23 incorporated in the blade support shaft 22 has one end hooked on the spring hook member 40 fixed to the shaft 22, and the other end hooked on the notch of the locking plate 20. . When the pressure knob 11 is operated to put pressure on the blade 31, the blade pressure is set to be determined by the torsional moment of the coil spring 23. The blade support shaft 22 is provided with spring hook members 40 on each of its four sides, so that the position at which the end of the torsion coil spring 23 is hooked can be changed. This is effective because it provides an adjustment function for variations in parts and assembly as well as various changes over time.

Further, a blade seal 41 is arranged at the end of the elastic cleaning blade 31 so as to be in contact with the blade 31, the screw pipe 32, and the locking plate 20.

4 is a sectional view of the shutter in the open state taken along line B-B' in FIG. 3, and FIG. 5 is a sectional view of the shutter in the closed state at the same position.

As is clear from FIG. 4, when the shutter/developer scooping member 19 is opened, the residual developer D adhering to the surface of the image carrier 1 is removed as the image carrier 1 rotates clockwise. The edge portion of the elastic cleaning blade 31 that comes into pressure contact with this removes the particles by rubbing, and the particles are deposited inside the screw pipe 33.
When the developer D eventually reaches the area of the conveying lead screw 33, it is carried toward the front side of the drawing by its conveying force, and is returned to the developing device through the developer recovery device from the drop opening in the front for reuse. Ru.

A back plate 34 is provided on the upper side of the elastic cleaning blade 31, and a blade holding member (for example, made of urethane foam material) 35 is provided on the lower side. Further, on the outside thereof, there are blade holders 36 and 37 that constitute the blade holder 7 shown in FIG. 1, and these are fixed on the blade support shaft 22 with the blade etc. sandwiched between them.

The parts integrated with these blades 31 in between rotate about the center of the blade support shaft 22 as a fulcrum, and are sealed with a fixed screw pipe 32 with a seal member 38. On the back side of the shutter/developer scooping member 19, that is, on the side of the image carrier, there is a scooping sheet 39 (located at a position facing the blade 31, which constitutes a part of the member 19, and the developer removed by the blade 31). A sheet that scoops up the drug and prevents backflow is attached. Of course, these may be integrated. The distance W between the rake sheet 39 and the blade edge can be arbitrarily set by adjusting the position of the stopper 24.

The interval W is preferably set to a length of 3 to 7 mm, which is sufficient for the removed developer to enter. If this gap is small, it is difficult to ensure sufficient developer flow, for example, 2 mm.
In some cases, the developer D may not fully enter the inside of the cleaning device and may fall to the lower left side of the image carrier 1. On the other hand, if this interval W is made too large, the developer D removed by the elastic cleaning blade 31 will not be pushed up to the region of the conveying lead screw 33, and there is a risk that it will spill from the sides or flow back from the scoop sheet 39.

In this embodiment, since the shutter lever 16 can be well controlled by the stopper member 24, the shutter member can be efficiently used even when functioning as a rake member.

In this embodiment, as will be described in detail in FIG. 6 below, two members 39- are provided at the tip of the shutter/developer scooping member 19 to improve the scooping function.
Although an example is shown in which a sheet member 39 made of No. 1,39-2 is attached, it is of course not limited thereto. For example, only the member 39-1 shown in the figure may be used.

This embodiment shows an example in which the scooping sheet 39 attached to the shutter/developer scooping member 19 is composed of two members.
As the first material, a thin and sturdy material such as a stainless steel plate for a spring or a PETP film is preferable. The member 39-2 is attached so as to wrap around one end of the member 39-1, and good results have been obtained using a plastic film with good sliding properties, such as a PETP film, an ultra-high molecular weight polyethylene film, or a polyimide resin film.

On the other hand, the material of the blade 31 in this embodiment is a polyurethane rubber sheet with a thickness of 1 to 4 mm and a rubber hardness of 55 to 70 degrees, and the contact angle θ to the image carrier is good at 1 to 30 degrees. Ta. Good results have been obtained when the blade thickness is 10 to 100 g/cm on the blade surface. Under these conditions of the scooping sheet 39 and blade 31, good cleaning can be achieved without causing scratches even on an image carrier having a relatively soft surface.

An example of a soft photoreceptor surface is vinyl chloride.
In some cases, a vinyl acetate copolymer is provided on a CdS or resin-based photosensitive layer.

By the way, as shown in FIG. 4, when an elastic body (having a larger elastic deformation rate than the blade material) is used as the elastic blade holding form 35 when holding the elastic cleaning blade 31, the blade that comes into contact with the image carrier is There is no risk of deformation of the edge due to tightening, the straightness of the edge can be guaranteed, and the risk of poor cleaning is eliminated. This is particularly preferred in the case of thin blades (for example, on the order of 1 to 4 mm thick). This is because, if the illustrated blade holding form 35 is not used, the blade may be directly tightened by a rigid member such as a holder, and the blade edge may be deformed into a wavy shape. If cleaning is performed in such a state, it is impossible to expect good cleaning.

On the other hand, as shown in FIG. 5, when the shutter/developer scooping member 19 is closed, the scooping sheet 39 attached to the tip of the shutter/developer scooping member 19 is connected to the cleaning blade 31 separated from the image carrier. inserted between the image carrier,
Moreover, since a counterclockwise rotational force is applied to the shutter/developer scooping member by the spring 17-1, the opening near the edge of the cleaning blade is completely closed.

Therefore, there is no possibility that the recovered developer D will be scattered when the cleaning device is attached and detached.

FIG. 7 shows an external view of the present cleaning device as seen from the rear.

When installing this cleaning device on the main body of the machine, attach the rear plate 4 to the guide surface (not shown) on the main body side.
The guide portion 42-1 of No. 2 is placed thereon, and the device is pressed and inserted into the main body of the device. At this time, the cleaning device is several mm farther from the photosensitive drum surface than at the final setting.

When the cleaning device is pushed in in this way and the guide portion 42-1 reaches the innermost part of the guide surface on the main body side, only the innermost part of the guide surface on the main body side is not cut out. The guide portion 42-1 falls down and the cleaning device reaches the set position height. Conversely, when the cleaning device is pulled out, it is pulled out away from the surface immediately after the cleaning device is pulled out.

This configuration solves the following problems. Generally, in a detachable cleaning device, the cleaning device must be attached and detached in a place where there is a small gap between the cleaning device and the photosensitive drum, and sometimes the cleaning device is attached and detached while coming into contact with the photosensitive drum. In this case, the photosensitive drum may be scratched and the expensive photosensitive drum may become unusable.

The mechanism of this embodiment solves the above problem because it allows the cleaning device to be operated as far away from the photosensitive drum surface as possible when attaching and detaching the cleaning device.

In the above embodiments, an example has been described in which the image bearing member is disposed near the top of the drum-shaped image carrier, but it is of course applicable to a case where the image carrier is disposed on the side surface or at the bottom.

(3) Effects of the invention As explained above, the present invention provides a cleaning device equipped with a cleaning blade.
During cleaning, the tip of the shutter/developer scooping member is placed opposite the cleaning blade to scoop up the removed developer, and as the cleaning blade is separated from the image carrier, the tip of the shutter/developer scooping member is placed opposite to the cleaning blade. Since the part is inserted between the blade and the image carrier, the developer stored in the cleaning device does not dissipate again and contaminate the charger and other parts in the image forming device. In addition to preventing image deterioration due to scattering phenomena, maintenance,
When the cleaning device is taken outside for repairs or the like, it has the effect of protecting the tip of the blade and preventing damage to it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an image forming apparatus to which a cleaning device according to the present invention is applied, FIG. 2 is a perspective view showing an operating mechanism of the cleaning device according to the present invention, and FIG. 3 is a perspective view of the operating mechanism shown in FIG. Some floor plans,
Figure 4 is a cross-sectional view of the shutter in Figure 3 B-B' when it is open, Figure 5 is a cross-sectional view of the same shutter when it is closed, Figure 6 is an explanatory diagram showing the structure of the scoop sheet, and Figure 7 is a cleaning FIG. 3 is a rear view of the device. 1... Image carrier, 19... Shutter and developer scooping member, 31... Cleaning blade.

Claims (1)

[Scope of Claims] 1. A cleaning device for removing developer remaining on an image carrier, comprising: an elastic cleaning blade that comes into contact with the image carrier and removes the developer on the image carrier; a movable first support means that supports the image carrier so that it can assume an operating position in which it contacts the image carrier and a retracted position in which it retreats from the operating position; and a developer removed from the image carrier by the elastic cleaning blade. a shutter-cum-developer-scooping member for preventing the developer from scattering; and the shutter-cum-developer-scooping member is disposed upstream of the elastic cleaning blade so as to face the elastic cleaning blade and abut against the image carrier. a movable second support means that supports the elastic cleaning blade so that it can take an operating position for scooping up the developer removed by the cleaning blade, and a closed position for retracting from the operating position and closing the elastic cleaning blade portion;
The second support means is moved in conjunction with the movement of the first support means, and the shutter and developer is moved into the gap between the image carrier and the elastic cleaning blade, which is created when the elastic cleaning blade is separated from the operating position. A cleaning device comprising an actuating means for sinking the tip of a scooping member into a closed state to prevent developer from scattering.