JPH08115024A - Cleaner - Google Patents

Abstract

PURPOSE: To sufficiently scrape off developer sticking to a fur brush by adjusting an amount that a scraping member encroachs into the fur brush during the rotation of the fur brush to at least two different amounts. CONSTITUTION: The fur brush 16 which rotates sliding against a rotary, drum- like photoreceptor 14 is provided in the housing 12 of a cleaner 10. An elliptically cylindrical flicker bar 18 for scraping off toner sticking to the fur brush 16 is also provided. This flicker bar 18 turns freely around a turning center 18a by means of a motor. By turning the flicker bar 18, a distance from the center of the fur brush 16 to the part of the flicker bar 18 that is the closest to the center of the fur brush 16 varies. Thus, the amount that the flicker bar 18 encroachs into the fur brush 16 can be adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer which remains on an image carrier after transfer in an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer which develops with a developer such as toner. The present invention relates to a cleaning device that removes mechanically.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic system has been widely spread. This electrophotographic image forming apparatus normally charges a drum-shaped image carrier (photosensitive drum) uniformly, and emits light carrying information of an image recorded on a document to the photosensitive drum. The electrostatic latent image is formed on the photosensitive drum by irradiating the surface of the photosensitive drum, and the electrostatic latent image is developed with a developer (toner), and the developed image is directly transferred to a sheet through a transfer drum or the like. Is a device that obtains a printed (copied) image by performing. This electrophotographic image forming apparatus is provided with a cleaning device that removes the developer remaining on the image carrier after transfer. As this cleaning device, a cleaning device configured to mechanically peel off the developer remaining on the image bearing member after transfer by mechanically peeling the fur brush so as to be in sliding contact with the image bearing member is widely used. . In this type of cleaning device, when a part of the developer peeled off from the image carrier adheres to the fur brush, the cleaning performance of the fur brush is deteriorated. Therefore, a developer called a flicker bar (Flicker Bar) is used. Conventionally, a technique of scraping off the developer adhering to the fur brush using a scraping plate-shaped scraping member has been used. As one of such techniques, the actual Kaihei 4-6534
Japanese Patent Publication No. 3 discloses a technique in which the flicker bar is fixed, the flicker bar is bitten into the fur brush, and the developer adhering to the fur brush is scraped off. However, normally, when the number of copies increases, the fur brush becomes worn, and thus the biting amount of the flicker bar decreases, and there is a problem that the developer attached to the fur brush cannot be sufficiently scraped off. Also, a technique of using a shaft instead of the flicker bar is known, but in that case,
There is a problem similar to the above.

As a technique for solving this problem, the biting amount of the flicker bar into the fur brush is increased,
Although it is conceivable to scrape off the developer that has adhered to the fur brush even if the fur brush is worn out, this technology has a large amount of bite into the flicker bar, which causes the fur brush and fur brush to violently rotate when the fur brush rotates. There is a problem in that the fur brush is worn away due to contact with the fur brush, and the fur brush has a large set.

Further, in Japanese Patent Laid-Open No. 4-152380, the flicker bar is separated from the fur brush when the fur brush is not rotating, and the flicker bar is made to bite into the fur brush while the fur brush is rotating. Techniques for suppressing wear and fatigue have been disclosed. However, this technique has a problem that it is impossible to sufficiently scrape off the developer attached to the fur brush that has once settled.Therefore, in order to sufficiently scrape off the developer, the bite amount of the flicker bar is increased. If left unattended, there arises a problem that abrasion and fatigue of the fur brush cannot be suppressed.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a cleaning device capable of sufficiently scraping off the developer adhering to the fur brush.

[0006]

A cleaning device of the present invention for achieving the above object forms a latent image on an image carrier, develops the latent image with a developer, and transfers the developed image to a transfer material. In the image forming apparatus, in the cleaning device for removing the developer remaining on the image carrier after transfer by using the fur brush that is rotatable in a roll shape and is in sliding contact with the image carrier, the fur brush is at least rotated. The scraping member is disposed at the bite position and scrapes off the developer adhering to the fur brush, and the biting amount of the scraping member during rotation of the fur brush is adjusted to at least two different amounts. A fur brush and / or a moving means for moving the scraping member are provided.

It is preferable that the moving means separates the scraping member and the fur brush from each other when the fur brush is not rotating. Also,
It is preferable that the moving means increases the bite amount as the operating time of the image forming apparatus elapses.

[0008]

According to the cleaning device of the present invention, the fur brush and / or the scraping member are moved by the moving means,
The biting amount of the scraping member during rotation of the fur brush is adjusted to at least two different amounts. Therefore, when the number of copies is small and the fur brush has little or little settling, the developer adhering to the fur brush is scraped off by adjusting the scraping member so that the biting amount is small. Further, when the number of copies increases and the fur brush becomes large in settling, the developer adhering to the fur brush is scraped off by adjusting so that the scraping member bites into the fur brush. As a result, the developer adhering to the fur brush can always be sufficiently scraped off even before the fur brush sags.

If the moving means separates the scraping member and the fur brush from each other when the fur brush is not rotating, the scraping member does not bite into the fur brush when the fur brush is not rotating. , It is possible to suppress the fatigue of the fur brush. Further, when the moving means increases the amount of scratching of the scraping member with the lapse of the operating time of the image forming apparatus, the moving unit is usually increased with the lapse of the operating time of the image forming apparatus according to the settling. Since the amount of bite of the scraping member increases, the developer adhering to the fur brush can be scraped off more sufficiently.

[0010]

Embodiments of the cleaning apparatus of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a schematic view showing a first embodiment of a cleaning device. In the housing 12 of the cleaning device 10, there is provided a fur brush 16 which is in sliding contact with the drum-shaped photoconductor 14 which rotates in the direction indicated by the arrow 14a and which rotates in the direction indicated by the arrow 16a. Further, the cleaning device 10 is also provided with an elliptically columnar flicker bar 18 (an example of a scraping member in the present invention) for scraping off the toner attached to the fur brush 16, and the flicker bar 18 has a rotation center 18a. Centered on arrow 18
A motor (not shown) (an example of moving means in the present invention) is configured to be rotatable in the direction indicated by b. The developing device 10 is also provided with a cleaning blade 19 so as to further remove the toner remaining on the photoconductor 14 which cannot be completely removed by the fur brush 16.

Here, as shown in FIG. 2, the radius of the fur brush 16 when there is no settling is r, and the maximum value of the distance from the rotation center 18a of the flicker bar 18 to the tip of the flicker bar 18 is L1. , And the minimum value is L2. Also,
From the center 16b of the fur brush 16 to the flicker bar 18
Of the value when the distance to the closest to the center 16a is maximized d _2, the value when a minimum and d _1, d ₁
And as d ₂ both smaller than the diameter r, namely setting the L1, L2 such that d ₁ <d ₂ <r. By rotating the flicker bar 18 with the setting as described above, from the center 16b of the fur brush 16 to the flicker bar 18,
The distance to the portion closest to the center 16a can be changed so as to have a value between d ₁ and d ₂ , so that the biting amount of the flicker bar 18 into the fur brush 16 can be adjusted. Therefore, for example, by increasing the bite amount according to the settling of the fur brush 16, the toner attached to the fur brush 16 can be sufficiently removed.

FIG. 3 shows a flicker bar 18 (see FIG. 1).
A modification of is shown. The flicker bar 20 shown in FIG. 3 is a columnar one in which a protrusion 20a extending in the longitudinal direction is formed, and the flicker bar 20 shown in FIG. It functions similarly to the flicker bar 18 shown. [Second Embodiment] FIGS. 4 and 5 are schematic views showing a second embodiment of the cleaning device.

Inside the housing 32 of the cleaning device 30, there is provided a fur brush 34 which is in sliding contact with the photoconductor 14 and rotates in a direction indicated by an arrow 34a. Further, the cleaning device 30 is also provided with a flicker bar 36 for scraping off the toner adhering to the fur brush 34,
The front end portion 36a of the flicker bar 36 bites into the fur brush 34, and the rear end portion 36b is connected to a solenoid 38 (an example of the moving means in the present invention). As shown in FIG. 4, the flicker bar 36 is moved by the solenoid 38.
It is also possible to adjust so that the tip end portion 36a of the flicker bite bites only slightly into the fur brush 34, and as shown in FIG. Although not shown, the tip portion 36 a of the flicker bar 36 can be separated from the fur brush 34. The developing device 30 of this embodiment is also provided with a cleaning blade 39.

An example of a method of adjusting the flicker bar 36 in the embodiment shown in FIGS. 4 and 5 will be described with reference to FIG. Here, a method of adjusting the bite amount of the flicker bar based on the number of copies is shown. Fur brush 3
4 (see FIG. 4) starts to rotate, the flicker bar 3
The solenoid 38 (see FIG. 4) is controlled so that the tip portion 36a of No. 6 slightly bites into the fur brush 34, and counting of the number of copies is started (S100). Here, since the bite amount is adjusted with the number of copies of 50,000, it is judged whether or not the number of copies is 50,000 (S102). When the number of copies reaches 50,000, the flicker bar 36 to the fur brush 34 is determined. Tip portion 36a of
The solenoid 38 is controlled so as to increase the bite amount of. By controlling the bite amount of the flicker bar by using the solenoid 38 in this way, even when the number of copies is small, even when the number of copies is large and the fur brush comes down, the toner adhered to the fur brush Can be scraped off sufficiently. Further, when the fur brush is not rotating, the tip of the flicker bar can be separated from the fur brush to prevent the fur brush from settling.

In the above adjusting method, the number of copies is used as a reference, but the rotation time and the number of rotations of the photoconductor 14, the rotation time and the number of rotations of the fur brush 34, the charging time for charging the photoconductor 14, the photoconductor 14 Developing time and the number of times of developing the latent image formed on the, the supply time and the number of times of supplying the toner to the developing device, the amount of toner removed from the photoreceptor by the cleaning device, and the photoreceptor for forming the latent image. The exposure time for exposure and the number of exposures can be used as a reference. When counting the number of copies, the number of copies may be converted into the number of copies when an A4 size original is copied in the longitudinal direction.

Further, the amount of biting of the flicker bar into the fur brush may be changed by a factor other than the temporal factor. For example, depending on the size of the original, an inter-image portion without toner adheres to the surface of the photoconductor, but a portion of the fur brush that is in sliding contact with the inter-image portion does not bite the flicker bar. May be Furthermore, since the toner is used as a lubricant, it may be adjusted to increase the amount of biting of the flicker bar when the toner is forcibly attached to the photoconductor. Furthermore, since a large amount of toner remains on the photoconductor when a jam occurs, it may be adjusted to increase the bite amount of the flicker bar. Furthermore, when the density of the developed image is too high, toner may be forcibly adhered to the inter-image area to reduce the toner density and reduce the density of the developed image to an appropriate value. Since a large amount of toner adheres to the brush,
It may be adjusted to increase the amount of biting of the flicker bar. By adjusting the biting amount of the flicker bar according to various factors in this manner, the toner attached to the fur brush can be scraped off sufficiently.

[Third Embodiment] FIGS. 7 and 8 are schematic views showing a third embodiment of the cleaning device. In these figures, the same elements as those of the cleaning device of the second embodiment shown in FIGS. 4 and 5 are designated by the same reference numerals. A feature of the cleaning device 40 of the third embodiment is that the amount of biting of the flicker bar 36 into the fur brush 34 is adjusted by using a cam 42 (an example of the moving means in the present invention). Even if the bite amount is adjusted using the cam 42 as described above, the same effect as that of the cleaning device 30 shown in FIGS. 4 and 5 is obtained.

[Fourth Embodiment] FIGS. 9 and 10 are schematic views showing a fourth embodiment of the cleaning device. In these figures, the same elements as those of the cleaning device of the second embodiment shown in FIGS. 4 and 5 are designated by the same reference numerals. The cleaning device of the fourth embodiment is characterized in that the flicker bar 36 is fixed to the housing 32, and the fur brush 34 is moved to move the flicker bar 3 to the fur brush 34.
The point is that the bite amount of 6 is adjusted. The fur brush 34 is moved by a solenoid 52 (an example of the moving means in the present invention) connected to the rotation center shaft 34a of the fur brush 34. As described above, even if the bite amount is adjusted by moving the fur brush 34 using the solenoid 52, the cleaning device 3 shown in FIGS.
An effect similar to 0 is produced.

[0019]

As described above, according to the cleaning device of the present invention, since the fur brush and / or the scraping member are adjusted to at least two different biting amounts by the moving means, the developer adhered to the fur brush. Can be scraped off sufficiently.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of a cleaning device of the present invention.

FIG. 2 is a schematic diagram showing a method of adjusting the bite amount of the flicker bar shown in FIG.

FIG. 3 is a schematic diagram showing a modified example of the flicker bar shown in FIG.

FIG. 4 is a schematic diagram showing a second embodiment of the cleaning device of the present invention, showing a state in which the flicker bar slightly bites into the fur brush.

FIG. 5 is a schematic view showing a second embodiment of the cleaning device of the present invention, showing a state in which a large amount of flicker bars bite into a fur brush.

6 is a flowchart showing an example of a method of adjusting the bite amount of the flicker bar shown in FIG.

FIG. 7 is a schematic view showing a third embodiment of the cleaning device of the present invention, showing a state in which the flicker bar slightly bites into the fur brush.

FIG. 8 is a schematic view showing a third embodiment of the cleaning device of the present invention, showing a state in which a large amount of flicker bars bite into a fur brush.

FIG. 9 is a schematic view showing a fourth embodiment of the cleaning device of the present invention, showing a state in which the flicker bar slightly bites into the fur brush.

FIG. 10 is a schematic view showing a fourth embodiment of the cleaning device of the present invention, showing a state where a large amount of flicker bars bite into a fur brush.

[Explanation of Codes] 10 Cleaning Device 16 Fur Brush 18 Flicker Bar 20 Flicker Bar 38 Solenoid 42 Cam 52 Solenoid

Claims (3)

[Claims] 1. An image forming apparatus for forming a latent image on an image carrier, developing the latent image with a developer, and transferring the developed image to a transfer material. In a cleaning device that removes the developer remaining on the image carrier after transfer using a different fur brush, the cleaning device is arranged at a position where it bites into the fur brush at least during rotation, and scrapes off the developer adhering to the fur brush. A scraping member, and a moving unit that moves the fur brush and / or the scraping member so that the biting amount of the scraping member during rotation of the fur brush is adjusted to at least two different amounts. Cleaning device characterized by: 2. The cleaning device according to claim 1, wherein the moving unit separates the scraping member and the fur brush from each other when the fur brush is not rotating. 3. The cleaning device according to claim 1, wherein the moving unit increases the bite amount as the operating time of the image forming apparatus elapses.