JPH0723982B2 - Cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an inorganic photoconductive photoconductor such as selenium, an organic photoconductive photoconductor such as polyvinylcarbazole, or a dielectric such as polycarbonate. The present invention relates to a cleaning device for an electrostatic recording device used as the above, and more particularly to a blade cleaning device that removes residual toner adhering to the surface of an image carrier with a blade.

[Prior art]

Generally, in an image forming apparatus to which an electrophotographic method is applied, such as an electrophotographic copying apparatus, a photoconductor having a photoconductive layer as an image carrier is formed in a drum shape, and a copy image of an original is formed by rotating the photoconductor. To form. In the above apparatus, a charging unit and a developing unit are arranged around the rotating photosensitive member, an electrostatic latent image is formed according to an original image, and a phenomenon is caused by the developer. The developed image on the photoreceptor obtained by development is then electrostatically transferred to a transfer material such as plain paper, and the developed image is fixed on the transfer material for use. On the other hand, after the transfer, the residual developing agent is removed from the photoconductor by the cleaning means, and the photoconductor is prepared for the next copy image formation.

Here, a blade cleaning device is widely used as the cleaning means. This blade cleaning is a method in which an elastic plate such as urethane rubber is pressed against the surface of the photosensitive member, one side of the elastic plate is supported by a holder, and the elasticity of the blade is used to press the edge of the opposite side against the photosensitive surface. This is a method in which the residual material such as toner is slid and removed at the edge portion by relatively moving. The feature is that the cleaning performance is superior to other cleaning methods,
The residual powder after cleaning is small, and the cleaning performance is maintained for a long time.

However, this blade cleaning method has the following drawbacks.

That is, when the blade is in strong pressure contact while being elastically deformed on the photoreceptor surface for a long time, the blade is permanently deformed to reduce its pressure contact force, or the tip of the blade partially lifts to cause uneven cleaning, There is a drawback in that the blade vibrates due to fluctuations in the friction between the blade and the photoconductor, damaging the surface of the photoconductor and generating noise. Also,
When the photoconductor stops its rotation, the photoconductor is locally pressed by the blade to the pressing position, so that the relatively strong local pressure changes the characteristics of the photoconductor, resulting in image formation. Cause trouble.

In order to avoid such a drawback of the blade cleaning method, when the copying machine is not used, that is, when the rotation of the photoconductor is stopped, the pressure contact of the blade is released and the blade is separated from the photoconductor, and the power of the copying machine is turned on. A mechanism has been proposed in which the pressure of the blade is applied in association with the rotation of the photoconductor each time or at the start of copying. However, this pressure release mechanism requires a mechanism that works in conjunction with a motor, a gear, etc., and has a drawback that the mechanism is complicated. Alternatively, there is a method in which the blade is moved to the pressure contact release position when the copying machine is packed, and the lock member is fixed with a screw, but the number of steps at the time of assembly or unpacking increases, and the operation is troublesome.

Recently, an image forming process unit integrally configured with an image forming unit including a photoconductor and a cleaning device arranged around the photoconductor is provided, and when the photoconductor is regularly replaced or repaired,
It is used to reduce the maintenance work by replacing it with the process unit (Japanese Patent Laid-Open No. 58-2126).
No. 2). In such a process unit, the cleaning device having the blade and the photoconductor can be integrally formed and exchanged, and therefore the unit and the photoconductor are stored outside the copying machine after assembly, and the blade and the photoconductor surface are kept under high pressure for a long period of time. If this happens, the new photoreceptor will be damaged, and this will hinder image formation during use.

Therefore, when the above process unit is shipped as a single unit, there has been proposed a means for reducing the influence of the blade on the surface of the photoconductor by switching the pressure of the blade to the photoconductor to a slightly pressure-bonded state.

However, when the process unit is loaded in the main body of the copying machine, a lever having a spring property is pushed against the rail side surface on the main body side of the copying machine so that the blade is pressed against the photoconductor. . In this way, when the process unit is packed and shipped in the main body of the copying machine and shipped, especially when it is stored in a hot and humid state, for example, in a stock state in a warehouse or in a container during transportation, It is highly possible that the blade under high pressure will damage the surface of the photoconductor.

As described above, in the case where the cleaning device is fixedly installed in the main body of the copier, the process unit is detachable, or the process unit is replaceable with the photoconductor, the blade and the photoconductor surface are long-term in any case. If it is left under strong pressure, permanent deformation of the blade and damage to the photoconductor
Affects normal copy records. As a means for avoiding such drawbacks, the crimp release mechanism and the lock mechanism also have a complicated structure and increase the number of parts, and increase the man-hours required for assembling and unpacking. In addition, there were problems such as increased costs.

[Object of the Invention]

An object of the present invention is to prevent deterioration of image forming characteristics due to damage of an image carrier due to local strong pressure contact of a blade of a cleaning device, and to prevent deterioration of cleaning characteristics due to permanent deformation of the blade. Another object of the present invention is to provide a cleaning device in which the durability of the blade is increased, the number of parts and the number of assembly steps are reduced, and the blade pressure contact force switching operation is easy.

[Structure of Invention]

The present invention is intended to achieve the above-mentioned object, which is provided in the vicinity of the peripheral surface of the image bearing member and is provided with a blade which comes into contact with the image bearing surface, and is left on the surface by the rotation of the image bearing member. In a cleaning device including a cleaning unit that cleans and removes the toner to be removed from the surface of the image carrier by a blade, a spring member biased by a spring in a direction to uniformly press the side end surface of the blade to the surface of the image carrier, and this spring. A switching member provided with a variable groove hole that makes the pressure of the spring variable by contacting / separating a member, and the switching member is bonded to the cleaning unit to form a spring in the variable groove hole of the switching member. When the members are fitted together, the pressure applied to the image carrier by the blade member is released from the blade member, the switching member is operated, and the spring member is ejected from the variable groove hole to switch the switching unit. It is accomplished by a cleaning apparatus characterized by adjusting the crimping force to the surface of the image bearing member of the blade tip into two stages by pressing the spring member on the inner surface of.

That is, according to the present invention, when the copying apparatus, the image forming process unit or the cleaning unit is shipped from the factory, a simple switching member is loaded into the cleaning apparatus to bring the blade into a slightly pressure-bonded state with respect to the image carrier to perform copying. When the apparatus is installed, it is possible to easily switch to a predetermined pressure contact state by pulling out the switching member, and to reduce the influence of the blade on the toner image forming surface layer of the image carrier.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

First, an embodiment of a copying machine to which the present invention can be applied will be described.

FIG. 1 is a front sectional view of a copying main body having an image forming process unit. In the figure, reference numeral 1 denotes a document placing table made of transparent glass, which reciprocates in the arrow direction. Reference numeral 2 denotes a converging optical transmission body array, which slit-exposes an original image placed on the original placing table 1 onto an image carrier 3, for example, a photosensitive drum. Reference numeral 4 denotes a charging electrode, which uniformly charges the photosensitive drum 3. The photosensitive drum 3 uniformly charged by the charging electrodes is subjected to image exposure by the converging light transmitting body array 2 to form an electrostatic latent image. Next, this electrostatic latent image is visualized by the phenomenon device 5.

On the other hand, the transfer paper P in the paper feed cassette 6 is transferred onto the photoconductor drum 3 by the second paper feed roller 8 which rotates at a timing so that the first paper feed roller 7 and the image on the photoconductor drum 3 are synchronized. Then, the toner image on the photosensitive drum 3 is transferred onto the transfer paper by the transfer electrode 9. After that, the transfer paper P separated from the photosensitive drum 3 by the separation electrode 10 is guided to the fixing device 11, and after the toner image on the transfer paper is fixed, the transfer paper P is discharged onto the paper discharge tray 13 by the paper discharge roller 12. It

After the transfer, the residual toner on the photosensitive drum 3 is a slow-charge electrode.
The voltage is gradually reduced by 14 and further cleaned by the cleaning device 15, and then the photoreceptor drum 3 is discharged by the low-voltage lamp 16.
The upper charge is completely erased, and the image forming cycle is performed again.

In this embodiment, an image forming process unit (hereinafter abbreviated as a unit) A is configured by integrating the photosensitive drum 3, the charging electrode 4, the slow-charging electrode 14, the cleaning device 15 and the like. In this unit A, a guide unit (not shown) fixedly provided on the main body of the copying machine and a sliding portion (not shown) of the unit A are fitted to each other so that the unit A can be attached to and detached from the main body of the copying machine. still,
When the unit A is loaded in a predetermined position on the main body, the unit A is positioned and fixed by a lock means (not shown).

FIG. 2 is a perspective view of the copying machine shown in FIG.
The state in the process of pulling out the unit A from the main body of the copying machine is shown. In the figure, the image forming means 3, 4, 14 and 15 are built in the housing 17 of the unit A.

FIG. 3 is a front sectional view of the unit A, FIG. 4 is a plan sectional view of the unit A seen from above, and FIG. 5 is a partially exploded perspective view. The state of being pulled out from the main body is shown. In these figures, 17
Is a housing containing the photosensitive drum 3, the charging electrode 4, the slow-charging electrode 14, and the cleaning device 15, and is formed of resin or the like. On the side wall surface of the housing 17, a window opened to the converging optical transmission medium array 2 for exposure, a phenomenon roll 5A of the phenomenon device 5
A window opened toward, a window for passing the slow-charging electrode 9 / separating electrode 10 and the transfer paper P, a window for transmitting light of the slow-charging lamp 16, and the like are provided.

Inside the cleaning device 15, a blade 18 for scraping off the toner on the photosensitive drum 3 and cleaning the surface of the photosensitive drum 3, and a holding plate for holding the blade 18 are provided.
19. A cleaning roller 21 that receives the toner scraped off by the blade 18 and conveys it to the toner box 20 below is provided.

In the opening above the housing 17 of the cleaning device 15,
The lid member 22 is screwed to the housing 17. A backup member 23 having the same overall length as the blade 18 or a little longer length is fixed to the lower surface of the lid member 22. The backup member 23 is made of a rigid material, for example, an aluminum alloy or a hard resin material. Further, the backup member 23 and the lid member 22 are made of a material which is not easily deformed by temperature because they are easily affected by the heat of the nearby dimming lamp 16, and are made of materials having substantially equal thermal expansion coefficients. For example, both are made of aluminum alloy material. Alternatively, both may be integrally molded using a hard resin having a low temperature deformation and high strength, such as an ABS resin, a polypropylene resin, or a polycarbonate resin. The lower surface of the backup member 23 is in contact with the upper surface of the free end of the blade 18 and serves to prevent deformation of the blade 18 when the photosensitive drum 3 rotates.

A swing fulcrum shaft 24 is fixedly projected on the upper surface side of the lid member 22, and a plate-shaped lever 25 is swingable around the fulcrum shaft 24. 26 is a stepped screw that prevents the lever 25 from rising. A stud 27 is fixedly projected on a part of the upper surface side of the lid member 22, and one end of a wire working spring 28 is locked to the stud 27. The wire-working spring 28 is a spring formed by molding a linear material into a required shape, and the other end has a thin coil spring 29.
The portion near the stud 27 at the intermediate portion contacts the side surface of the lever 25. The coil spring 29 is hooked on the wire-working spring 28 and the respective ends of the lever 25 and is pulled.

A stud 30 is planted and fixed to one end of the lever 25, and the lower end of the stud 30 is fixed to the holding plate by a stepped screw 31.
19 is rotatable. That is, the holding plate 19 can be swung.

When the unit A is taken out from the main body of the copying machine, the elastic force of the wire-working spring 28 pulls the lever 25 via the coil spring 29. Therefore, the wire-working spring 28 is separated from the side surface of the lever 25. Stud 30 fixed to 25
The tip of the blade 18 is lightly pressed onto the surface of the photosensitive drum 3 via the stepped screw 31 and the holding member 19. This crimping force determines the tensile force of the coil spring 29 so that the total length of the blade is about 500 mm and about 500 g.

Next, the unit A is inserted into the main body of the copying machine. FIG. 6 is a plan sectional view showing that the unit A is completely inserted. In this state, the right end of the wire-working spring 28 of the unit A is slidably contacted with the inner surface of the rail member 32 of the main body of the copying machine to be elastically changed, and the lever 25 has the coil spring 29 centered on the fulcrum shaft 24 and the wire-working spring 28. Press the lever 25 at the bent part of the
Swing clockwise around. As a result, the tip of the blade 18 strongly presses the surface of the photosensitive drum 3 with a predetermined pressure. At this time, the blade 18 to the photosensitive drum 3
Set the wire diameter, length, shape, and amount of blade movement of the wire work spring so that the crimping force is about 2.5 kg for a total blade length of about 300 mm.

On the other hand, the change of the crimping force of the blade 18 is performed by the procedure reverse to the above, and the pressing force is reduced by the detaching operation of the unit A.

In this way, the pressing force of the blade 18 onto the photoconductor 3 is maintained in a slightly pressed state when the unit A is taken out of the copying machine main body, for example, when the unit A is shipped as a single unit, The influence of the blade 18 on the surface of the body 3 is reduced. Next, when the unit A is mounted in the main body of the copying machine, the unit is kept in the strongly crimped state, and when the unit A is taken out again, the unit is automatically switched to the slightly crimped state.

However, when the above unit A is separately packaged for replacement in the market and shipped from the factory, and when it is shipped from the factory, it is in a finished product state in which the unit A is loaded in the copying machine body. It is considered that copying is started immediately.

Therefore, in the present invention, with the unit A loaded in the main body of the copying machine, by inserting a switching member described below between the main body of the copying machine and the unit A, the blade for the photoconductor is brought into a slightly pressure-bonded state, and in this state the factory shipment However, when the copying machine is installed at the user's predetermined position, the blade is easily switched to the pressure-bonding state by pulling out the switching member to set the copying start standby state.

7 (A) and 7 (B) are a perspective view and a plan view of the switching member 33. In the figure, the switching member 33 is made of a hard thin plate, for example, an iron plate of about 0.5 mm, and the flat plate portion forming the insertion portion has a flat cam shape. That is, on the upper surface side facing the reference surface 33A on the bottom side, the valley portion 33B forming the cam height of the low parallel surface and the peak portion 33C forming the cam height of the high parallel surface.
And inclined surfaces 33D and 33E connecting the peak portion 33C and the valley portion 33B. 33F is an L-shaped finger rest,
When inserting / pulling out the switching member 33, it becomes a finger grip.

FIG. 8 is a view showing a state in which the unit A is loaded in the main body of the copying machine, FIG. 8 (A) is a side view, and FIG. 8 (B).
Is a front sectional view.

On the side surface of the rail member 32 fixed inside the main body of the copying machine, a slightly inclined slit 33A is opened. Since the slit 33A is opened at a position higher than the mounting position of the wire-working spring 28, the wire-working spring 28 is strongly pressed against the inner side surface of the rail member 32, and as a result, as shown in FIG.
The wire-work spring 28 is strongly bent to press the lever 25 firmly. As a result, the blade 18 strongly presses the surface of the photoconductor 3 with a predetermined pressure to exert a cleaning effect.

FIG. 9 is a view showing a state in which the unit A is loaded in the main body of the copying machine and is shipped from the factory. FIG. 9 (A) is a side view and FIG. 9 (B) is a front sectional view thereof. is there.

When the copying machine is shipped from the factory, the switching member 33 is set to the unit A described above.
And the rail member 32 are inserted in advance. That is, the switching member 33 is brought into contact with the inner bottom surface of the rail member 32,
If it is inserted into the gap, the inclined surface 33D of the switching member 33 pushes up the lower surface of the wire-working spring 28 while pressing the lower surface of the wire-working spring 28 as the switching member enters, and the wire-working is made just before slidingly contacting the mountain portion 33C of the switching member 33. The tip of the spring 28 has a slit 32 in the rail member 32.
It is lifted to the position A, and springs out of the slit 32A having an opening shape and stops there, and the state shown in FIG. 4 is obtained. In this state, the spring 28 is separated from the lever 25, and the lever 25 is rotated about the shaft 24 by the coil pan 29 having a weak tensile force. As a result, the tip edge of the blade 18 slightly moves from the surface of the photoconductor 3,
It will be in a slightly crimped state.

Next, after the copying machine is installed and before starting copying, the switching member 33 is first pulled out from the copying machine main body. by this,
The inclined surface 33E and the flat surface portion 33G of the switching member 33 are formed by the wire-working spring 28.
Is pushed back to the inside of the rail member 32, and is moved from the slit 32A to the inner surface of the rail member 32 by the tensile force of the coil spring 29. When the wire-working spring 28 comes into contact with the inner surface of the rail member 32, the lever 18 strongly presses and swings the lever 25 again by its own spring property, whereby the blade 18 comes into strong contact with the surface of the photoconductor 3 at a predetermined pressure. , Copyable state.

In the above description, the switching member is inserted and used to keep the blade and the photosensitive member in a slightly pressure-bonded state between the factory shipment of the copying machine and the user's market setting. It may be discarded, but even after the user uses the copying machine, when the copying machine is not used for a long period of time, the switching member is reinserted to protect the photoconductor and the blade and maintain their performance. It can also be used for purposes.

Further, if the shape of the switching member is slightly changed so that the switching member can be slid by the conversion switch and the electric member, it is possible to extend the life of the photoconductor and the blade by switching between strong pressure bonding and slight pressure bonding at any time. .

Although the above description relates to the attachment / detachment of the process unit including the photoconductor, even when only the cleaning device is attached / detached, if the switching member is applied, it is possible to easily switch the strong pressure / fine pressure bonding of the blade. is there.

〔The invention's effect〕

As described above in detail with reference to specific examples, the cleaning device of the present invention allows the blade to be installed by inserting the switching member even when both image forming process units are removed from the main body of the copying machine or even when they are installed. Since it is held in a slightly pressure-bonded state with respect to the photoconductor, there is no fear of wear of the photoconductor and the blade due to strong pressure of the blade, and stable image formation is possible for a long period of time.

In addition, a special power source is not required for pressing and releasing the blade, and the operation is reliable and the operability is good because it is easily performed by manually inserting or pulling out a simple switching member.

Furthermore, since the relative position between the blade and the photoconductor can be changed slightly by switching between strong pressure bonding and slight pressure bonding, the relative position for proper cleaning that was initially set can be easily restored and maintained, and cleaning performance is always maintained. It is stable, and stable image formation is possible for a long period of time.

[Brief description of drawings]

FIG. 1 is a front sectional view of an image recording apparatus of a specific example based on the present invention, FIG. 2 is a perspective view of a copying machine showing a state in which an image forming process unit is inserted and removed, and FIG. 3 is an image forming process unit. Front sectional views, FIGS. 4 and 5 are plan sectional views and exploded perspective views when the unit is taken out, and FIG. 6 is a plan sectional view when the unit is mounted, FIGS. 7 (A) and (A). B) is a perspective view and a plan view of the switching member,
8 (A) and 8 (B) are side and front views showing the relation of the rail member peripheral members when the switching member is removed.
9 (A) and 9 (B) are a side view and a front view showing the relation of the rail member peripheral members when the switching member is inserted. 3 ... Photoconductor, 18 ... Blade 25 ... Lever, 28 ... Wire-working spring 29 ... Coil spring, 32 ... Rail member 32A ... Slit, 33 ... Switching member 33D ... Inclined surface

Claims (1)

[Claims] 1. A blade which is disposed in the vicinity of the periphery of the image carrier and is in contact with the surface of the image carrier, and the toner remaining on the surface of the image carrier is rotated by the blade to rotate the image carrier surface. In a cleaning device comprising a cleaning unit for cleaning and removing from the above, a spring member biased by a spring in a direction in which the side end surface of the blade is uniformly pressed against the surface of the image bearing member, and the spring member is contacted with and separated from the spring member. A switching member having a variable groove hole for making the pressure of the spring variable, and the spring member when the switching member is mounted on the cleaning unit and the spring member is fitted in the variable groove hole of the switching member. Release the pressure contact of the blade tip to the image carrier by the operation, operate the switching member, let the spring member escape from the variable groove hole, and press the spring member on the inner surface of the switching member. Cleaning apparatus characterized by further adjusting the pressing force to the blade tip surface of the image bearing member of the two stages.