JPH05297754A - Fixing unit cleaning device for electrophotographic device - Google Patents

Abstract

PURPOSE:To prolong the life of the blade of a fixing unit cleaning device, to prevent toner scraped from a fixing member from adhering to the tip of the blade or from being melted and stuck to the tip of the blade because of heat at the time of fixing, and to prevent the staining of an image surface. CONSTITUTION:The blade 41 is provided to freely turn between a cleaning position where the tip of the blade 41 is pressed on a fixing roller 21 being the fixing member of a fixing unit 20 and a retreat position where pressing is released, and coupled with a solenoid 46 being a driving means. A toner receiver 44 is provided below the blade 41 and a cleaning member 45 is arranged in the toner receiver 44. Then, the toner adhering to the surface of the roller 21 is scraped and stored in the toner receiver 44, and also the tip of the blade 41 is cleaned by the cleaning member 45 when the blade 41 turns periodically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention records on a sheet by an electrophotographic system (a system for transferring an image formed on a photoconductor to a sheet for recording) such as a printer, a copying machine, and a facsimile using a laser. It can be applied to an electrophotographic apparatus. Specifically, in such an electrophotographic apparatus, it can be applied to a fixing device that rotates a fixing member to bring it into contact with an image surface of a sheet after image transfer and fix a toner image on the image surface. More specifically, in such a fixing device, the present invention relates to a fixing device cleaning device for pressing the tip of a blade against the surface of the fixing member to scrape off the toner adhering to the surface.

[0002]

2. Description of the Related Art Conventionally, a fixing device cleaning device of this type has a structure in which a blade is constantly pressed against the surface of a fixing member of the fixing device. Then, at the time of image fixing, the toner adhering to the surface of the rotating fixing member is scraped off with a blade for cleaning.

[0003]

However, in the above-mentioned fixing device cleaning device, since the blade is constantly pressed against the fixing member, the tip of the blade is worn and the life of the blade is shortened. Further, the toner scraped off from the fixing member adheres to the tip of the blade, or the scraped toner adheres to the tip of the blade due to the heat at the time of fixing, so that the fixing member cannot be cleaned properly. In addition to the above, there is a problem in that toner particles adhered or welded to the blade adhere to the fixing member to stain the image surface of the sheet.

Therefore, an object of the present invention is to extend the life of the blade of the fixing device cleaning device, and toner which is scraped off from the fixing member adheres to the tip of the blade or is scraped off. -Is to prevent the image surface from being soiled by preventing it from being welded to the tip of the blade due to heat during fixing.

[0005]

Therefore, according to the first aspect of the present invention, a fixing member such as the fixing roller 21 of the fixing device 20 or the fixing belt 60 of the fixing device 20 is provided, for example, as shown in the following embodiments. In a fixing device cleaning device 40 of an electrophotographic apparatus in which the tip of a blade 41 is pressed against the surface to scrape off toner adhering to the surface, the blade 41 is driven by a driving means such as a solenoid 46. A cleaning member 45 is provided which is rotatable between a cleaning position for pressing against the fixing member and a retracted position for releasing the pressing, and a cleaning member 45 for cleaning the tip of the blade 41 when the blade 41 rotates. Characterize.

According to a second aspect of the present invention, for example, as in the following illustrated embodiment, in the fixing device cleaning device 40 of the electrophotographic apparatus according to the first aspect, the toner whose blade 41 is scraped off is used. A toner receiver 44 for receiving the toner is provided below the blade 41, and the cleaning member 45 is arranged in the toner receiver 44.

According to a third aspect of the present invention, the toner receiver 44 in the fixing device cleaning device 40 of the electrophotographic apparatus according to the second aspect is, for example, as in the embodiment shown in FIG.
A magnet 48 for attracting a toner is provided therein.

In the fixing device cleaning device 40 of the electrophotographic apparatus according to the second aspect of the present invention, the toner receiver 44 itself is provided, for example, as in the embodiment shown in FIG. 5 below. It is characterized by being magnetized.

[0009]

The blade 41 is periodically driven by the driving means to rotate between the cleaning position and the retracted position. When the blade 41 rotates, the tip of the blade 41 is cleaned by the cleaning member 45.

According to the second aspect of the present invention, the toner received by the blade 41 during cleaning is received by the toner receiver 44.

According to the third aspect, the blade 41
The toner scraped off by the magnet is attracted by the magnet 48 in the toner receiver 44.

According to the fourth aspect, the blur
The toner scraped by the blade 41 is attracted to the magnetized toner receiver 44.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 9 is a schematic diagram of the entire internal structure of a laser printer including a fixing device according to an embodiment of the present invention. Reference numeral 10 in the figure denotes the apparatus main body. A belt-shaped photoreceptor 11 is provided in the main body 10 of the apparatus at substantially the center thereof. Around the photoconductor 11,
The charger 12 and the developing device 1 are sequentially arranged in the driving direction indicated by the arrow in the figure.
3, the transfer device 14 and the cleaning device 15 are arranged. An optical writer 16 is arranged above the charger 12 and the cleaner 15. A paper feed cassette 17 is detachably attached to the lower right side of the apparatus body 10 in the figure.

The sheet sent out from the paper feed cassette 17 by the feed roller 18 in the direction of arrow A in the figure is conveyed to the lower side of the photoconductor 11 at a timing by the registration roller pair 19. The photoconductor 11 is driven in the clockwise direction as shown by the arrow, and at that time, the surface of the photoconductor 11 is uniformly charged by the charger 12, and the laser beam from the optical writing device 16 is irradiated to electrostatically charge the photoconductor 11. Form a latent image. This latent image is visualized by toner as it passes through the developing device 13. Then, this visible image is transferred by the transfer device 14 to the surface of the sheet conveyed to the lower side of the photoconductor 11. Then, the sheet after the image transfer is fixed to the fixing device 2 of the present invention.
The toner image is conveyed between the fixing roller 21 and the pressure roller 22 of 0, and the toner image is fixed. Then, the sheet exiting the fixing device 20 is discharged to the paper discharge unit 24 by the paper discharge roller 23. On the other hand,
After the image transfer, the cleaning device 15 removes the residual toner from the photoconductor 11 and the charge removing device 25 removes the charge.

As shown in FIG. 8, the above-mentioned fixing device 20 has a pressure roller 22 disposed below the fixing roller 21 which is a fixing means, supports the pressure roller 22 rotatably in the direction of the arrow, and applies pressure. The roller 22 is urged against the fixing roller 21 by appropriately urging the roller 22. And this fixing roller 21
The sheet after the image transfer is passed between the pressure roller 22 and the pressure roller 22 to apply pressure and heat thereto to fix the image. The fixing roller 21 is, for example, a sheet formed by electroforming as shown in FIG.
A nickel cylindrical tube (thickness 0.08-0.
A fluororesin layer (thickness 8 to 25 μm) 31 having good releasability is formed on the outer periphery of the (4 mm) 30. An aluminum tube (thickness 0.4 to 2.5 mm) may be used as the cylindrical tube 30. Then, as shown in FIG.
2 is provided.

By the way, in the fixing device cleaning device 40, as shown in FIG. 1, a long blade 41 is arranged along the axial direction of the fixing roller 21 on the sheet discharge side which is the left side of the fixing roller 21 in the figure. .. The blade 41 is made of polyimide or fluororesin and has a thickness of 0.05 to 0.3 mm and a width of 15 mm.
˜50 mm, and the length thereof is longer than the maximum paper passing width of 215.9 mm in the fixing roller 21.

As shown in FIG. 2, the blade 41 is provided with supporting shafts 42 projecting upward in the width direction (vertical direction in the drawing) from both ends in the length direction thereof, and the supporting shafts 42 are provided with the supporting shafts 42. It is inserted into the shaft holes 34 of both side plates 33 and is rotatably bridged between the side plates 33. As shown in FIG. 1, the blade 41 has a cleaning position indicated by a solid line where the tip of the blade 41 contacts the lower peripheral surface of the fixing roller 21 and the tip of the blade 41 is closer to the fixing roller 21 than the fixing roller 21. The support shaft 42 is rotatably provided at a retracted position indicated by a long and short dash line, which is largely separated.

A spring 43 is wound around the support shaft 42 as shown in FIG.
1, while the other end is hung on the side plate 33, the blade 41
Is always urged toward the retracted position. Below the blade 41, a toner receiver 44 having an open upper side is provided, and the side wall 44a opposite to the fixing roller 21 receives the blade 41 biased toward the retracted position and moves the blade 41. Regulate.
Then, on the inner bottom surface of the toner receiver 44, the blade 41
A cleaning member 45 for cleaning the tip of the is attached.

As shown in FIG. 1, a solenoid 46 is provided above the fixing roller 21 as a driving means of the present invention, the operation of which stops when a predetermined time elapses. The solenoid 46 includes an operating rod 46a, and an operating member 47 is attached to the tip of the operating rod 46a. As shown in FIG. 3, the operating member 47 includes a pressing plate portion 47a, a rod portion 47b rising from one side of the pressing plate portion 47a, and an arm portion 47c connected to the upper end of the rod portion 47b. The arm portion 47c is attached to the operating rod 46a, and the pressing plate portion 47 is attached.
a is brought into contact with the surface of the blade 41 opposite to the fixing roller 21.

When the solenoid 46 is actuated during fixing, the actuating rod 46a is retracted to move the actuating member 47 to the right, as shown in FIG. By this operating member 47, the blade 41 is rotated to the cleaning position against the spring 43, and the tip of the cleaning member 45 is rotated during the rotation.
After contacting and rubbing with, the roller is pressed against the peripheral surface of the fixing roller 21, and the tip end is directed in the counter direction with respect to the rotation direction of the fixing roller 21. Then, the toner adhering to the surface of the fixing roller 21 is scraped off by the blade 41 by heat and pressure at the time of fixing the image. The toner is collected in the toner receiver 44.

Then, when the preset time has elapsed, the operation of the solenoid 46 is stopped. Then, the blade 41 is rotated by the urging force of the spring 43. This is received by the side wall 44a of the toner receiver 44 to the retracted position shown by the alternate long and short dash line, and the blade 41 actuates the operating member 47.
Is pressed to return the operating rod 46a of the solenoid 46 to the projecting state. During the rotation to the retracted position, the blur
The tip of the blade 41 contacts the cleaning member 45 and is rubbed, and the toner attached to the tip is cleaned.

By the way, in the above-described embodiment, only the cleaning member 45 is provided in the toner receiver 44.
As shown in FIG. 5, a magnet 48 may be provided on the inner bottom surface of the toner receiver 44, and the magnet 48 may attract the toner scraped off by the blade 41.

Further, as shown in FIG. 5, the toner receiver 44
An electrode plate 49 is provided in place of the magnet 48, and the electrode plate 49
You may make it magnetize in the opposite magnetism with the toner.
As shown in FIG. 6, the toner receiver 44 may be formed of, for example, a conductive material so as to be magnetized so as to have a magnetic field reverse to that of the toner. In this case, even if the toner is not a magnetic toner,
Is always positively or negatively charged at the time of development, and thus the toner is attracted and accommodated in the toner receiver 44 without being scattered by the above configuration.

In the illustrated embodiment described above, the present invention is applied to the fixing device 20 in which the fixing roller 21 is arranged above the pressure roller 22 as shown in FIG. However, for example, as shown in FIG. 10, the fixing device 2 in which the fixing roller 21 is arranged below the pressure roller 22 is disposed.
The present invention can also be applied to 0. in this case,
For example, as shown in the figure, the blade 41 is arranged below the fixing roller 21. Also, in the above embodiment,
Although the cleaning member 45 is provided on the inner bottom surface of the toner receiver 44, it is attached to the inner surface of the other side wall 44b opposed to the side wall 44a for restricting the movement of the blade 41. And
When the blade 41 is rotated, the tip of the blade 41 is rubbed with the blade 41 for cleaning.

Further, although the fixing member is the fixing roller 21 in all the illustrated embodiments, the present invention is not limited to the fixing device 20 in which the fixing member is the fixing belt 60 as shown in FIG. Can also be applied. That is, the fixing device 20 spans the fixing belt 60 between the driving roller 61, the driven roller 62, and the ceramic heater 63, and sandwiches the fixing belt 60 between the ceramic heater 63 and the pressure roller 22.
Press against. As shown in FIG. 12, the fixing belt 60 includes a heat-resistant resin layer (having a thickness of 10 to 25 μm) such as polyimide.
m) Fluorine resin layer (thickness 8 to 25 μm) 6 on the outer periphery of 64
5 is formed.

In the case of this fixing device, as in the case of the fixing device 20 in which the fixing roller is arranged on the lower side, the fixing belt 60 is also provided.
The blade 41 is provided on the lower side, and the cleaning member 45 is attached to the inner surface of the other side wall 44b facing the side wall 44a that restricts the movement of the blade 41. When the blade 41 is rotated, the tip of the blade 41 is rubbed with the blade 41 for cleaning.

[0027]

According to the present invention, therefore, the blade is periodically rotated to the retracted position by the driving means, so that the blade life of the fixing device is extended and the blade is moved to the cleaning position. When rotating to the position, the tip of the toner is cleaned by the cleaning member, so the toner scraped from the fixing member adheres to the tip of the blade, or the scraped toner is heated by the heat during fixing. It is possible to prevent the tip of the blade from being welded and prevent the image surface from being soiled.

According to the second aspect of the present invention, the toner scraped off by the blade during cleaning is received by the toner receiver, so that the toner can be accommodated in the toner receiver without scattering.

According to the third aspect, since the toner scraped off by the blade is attracted by the magnet in the toner receiver, the toner can be reliably accommodated without scattering. ..

According to the fourth aspect of the present invention, since the blade scrapes the scraped toner into the magnetized toner receiver, the toner is also reliably accommodated without scattering. can do.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a fixing device cleaning device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an attachment portion of the blade.

FIG. 3 is a perspective view of an operating member that transmits the driving force of the solenoid to the blade.

FIG. 4 is a configuration diagram showing another example of the toner receiver.

FIG. 5 is a configuration diagram showing still another example of the toner receiver.

FIG. 6 is a configuration diagram showing still another example of the toner receiver.

FIG. 7 is a partial cross-sectional view of a fixing roller of a fixing device including the fixing device cleaning device.

FIG. 8 is a fixing roller of the fixing device provided with the fixing device cleaning device.
It is a schematic block diagram which shows arrangement | positioning of a la and a pressure roller.

FIG. 9 is an overall schematic configuration diagram showing an internal mechanism of a laser printer including the fixing device cleaning device of the present invention.

FIG. 10 is a blade, a toner receiver of a fixing device cleaning device in a fixing device in which a fixing roller is arranged below a pressure roller,
It is a schematic structure figure showing arrangement of a cleaning member.

FIG. 11 is a schematic configuration diagram showing an arrangement of a blade, a toner receiver, and a cleaning member of a fixing device cleaning device in a fixing device using a fixing belt.

FIG. 12 is a partial cross-sectional view of the fixing belt.

[Explanation of symbols]

 20 fixing device 21 fixing roller (fixing member) 40 fixing device cleaning device 41 blade 44 toner receiver 45 cleaning member 48 magnet 60 fixing belt (fixing member)

Claims (4)

[Claims] 1. A fixing device cleaning device for an electrophotographic apparatus, wherein a tip of a blade is pressed against the surface of a fixing member of the fixing device to scrape off toner adhering to the surface of the fixing device. While being rotatable between a cleaning position for pressing against the fixing member and a retracted position for releasing the pressing,
A fixing device cleaning device for an electrophotographic apparatus, comprising a cleaning member for cleaning the tip of the blade when the blade rotates. 2. A toner receiver for receiving a toner scraped off by the blade is provided below the blade, and the cleaning member is arranged in the toner receiver. A fixing device cleaning device for an electrophotographic apparatus according to 1. 3. The fixing device cleaning device for an electrophotographic apparatus according to claim 2, wherein a magnet for attracting the toner is provided in the toner receiver. 4. The fixing device cleaning device for an electrophotographic apparatus according to claim 2, wherein the toner receiver itself is magnetized.