JPS62113186A - Side sealing mechanism for cleaning device - Google Patents

Abstract

PURPOSE:To prevent the splashing of a toner from both ends of a blade by providing magnetic rollers in the hollow parts at both ends of a photosensitive drum in such a manner that the rollers can be rotationally driven and moving the toner, etc., scraped from the surface of the photosensitive body and deposited on the blade edge toward the center of the blade. CONSTITUTION:The magnetic rollers 11 are constituted by alternately providing magnets 11a, 11b positioned with S poles and N poles to the outside circumferential part around fulcrum shafts 8. Friction rollers 7 are driven to rotate in an arrow (b) direction according to the rotation of the photosensitive drum 1 and the rotating power thereof is transmitted to a worm 9. The magnetic rollers 11 are rotated in the same direction when a worm wheel 10 rotates in an arrow (c) direction. The magnetic conveying force to convey the magnetic material toward the center of the blade edge 6 is thereby formed along the blade edge 6 at both end of the edge 6. The toner which is scraped by the blade 5 from the surface of the drum 1, deposits on the edge 6 and is moved toward both ends of the blade 5 is subjected to the magnetic conveying effect in an arrow (d) direction by the magnetic rollers 11 by which the splashing of the toner from the end of the blade 5 is prevented.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a side seal mechanism in a cleaning device such as an electrophotographic copying machine. This invention relates to a side seal mechanism that prevents the blade from moving and scattering from both ends of the blade.

(Prior Art) Generally, an electrostatic latent image formed on the surface of a photoreceptor drum is
In an electrophotographic copying machine that supplies toner from a developing device to form a toner image and transfers the toner image onto copy paper, as shown in FIGS. 4 and 5, a photosensitive drum is used. (1), parallel to the axis of the photoreceptor drum (1),
In addition, a cleaning device (4) equipped with a blade (5) whose edge (6) comes into pressure contact with the surface of the photoreceptor drum (1) is provided to remove toner, etc. that still remains on the surface of the photoreceptor drum (1) even after transfer. We scrape it up and collect it.

However, in this case, as shown by the solid line in FIG. 5, toner etc. scraped from the surface of the photoreceptor drum (1) accumulates in front of the edge (6) of the blade (5). (6), and scatters from both ends of the blade (5), contaminating peripheral equipment, resulting in the problem that the inside of the equipment must be cleaned frequently.

In particular, if it adheres to the corona wire of a corona charger such as a charger or transfer charger installed on the side of the photoreceptor drum (+), the amount of corona discharge decreases, resulting in poor charging and transfer. It had

For this reason, conventionally, a side seal mechanism has been developed in which a sealing member made of sponge or the like is attached to both ends of the edge (6) of the blade (5) to prevent the scraped toner from scattering. Publication No. 1, and Japanese Unexamined Patent Publication No. 5
According to Publication No. 7-155577, the blade (5)
A device in which both ends were curved to protrude forward, and the curved portions were used to prevent toner from scattering, was published in 1983.
This is proposed by the publication No.-42000.

However, in the former case, the blade (5)
Since it is not possible to ensure close contact between the seal member and the photoreceptor drum (1), and the seal member is always in contact with the photoreceptor drum (1), the photoreceptor drum (1) or the seal member may wear out.
It has the disadvantage that it cannot provide a stable sealing effect over a long period of time.

In addition, in the latter case, since the main body and the curved portion of the blade (5) have different rigidities in the rotational direction of the photoreceptor drum (1), the photoreceptor drum ( 1), it has the disadvantage that it cannot be pressed uniformly and cannot sufficiently prevent the toner from scattering.

(Means for solving the problems) The present invention has been made to solve the problems mentioned above.
In the side seal mechanism of the cleaning device, a hollow portion formed at both ends of the electrostatic latent image carrier, and an axis orthogonal to the rotation axis of the electrostatic latent image carrier are provided at positions facing both ends of the blade edge of the hollow portion. It also has a magnetic roller with S and N poles sequentially magnetized in the circumferential direction, and a drive means that rotates the magnetic roller in a direction that moves the magnetic material toward the center of the blade. By applying a conveyance force toward the center of the blade to the magnetic developer moving to both ends of the blade, toner is prevented from scattering from the ends of the blade.

(Example) Hereinafter, the present invention will be described based on drawings which are one example.

In FIGS. 1 and 2, the photoreceptor drum (1) is an aluminum circular drum (I) whose surface is coated with a photoconductor.
A pair of flanges (2), (2) having a through hole (2a) in the center are installed inside the drum (1a) at a position slightly inside from both ends of the drum (1a), and a hollow part (S) is formed at both ends. A drive shaft (3) is fitted into the through hole (2a). The photosensitive drum (1) has a drive shaft (3) supported by side plates (3a), (3a), and can be rotated in the direction of arrow (a) by a drive source (not shown).

Further, around the photoreceptor drum (1), various devices (not shown) such as a charging charger, an exposure means, a developing device, a transfer charger, etc., and a blade (5) are arranged along the direction of arrow (a).
) (see FIG. 4) are sequentially arranged.

Note that the potential of the image portion (corresponding to the black background portion of the document) of the electrostatic latent image formed by the charger is 15
The potential applied to the charger and the amount of exposure by the exposure means are adjusted so that the potential of the background portion of the electrostatic latent image (corresponding to the white background portion of the document) is 50 V and 1200 V, respectively.

Further, the developing device accommodates a developing sleeve that faces the photoreceptor drum (1) at a predetermined interval, and this developing sleeve has a voltage for applying a developing bias voltage of -300V to the developing sleeve. A developing bias power source is electrically connected.

Furthermore, this developing device includes a small-diameter magnetic carrier having an average particle diameter of 20 μm and a resistance value of 10”Ω·CIN, and a small-diameter magnetic carrier having a resistance value of 10”
A two-component developer made of a mixture with an insulating toner having an average particle size of 11 μm and having a resistance value of Ω·cm or more is stored.

That is, by setting each device in this way, the surface of the photoreceptor drum (1) corresponding to the background part of the electrostatic latent image,
The small-diameter magnetic carrier in the two-component magnetic developer is attached, and the insulating toner is electrostatically attached to the surface of the photoreceptor drum (1) corresponding to the image area of the electrostatic latent image. be.

The above technique is disclosed in Japanese Patent Laid-Open No. 57-64280.

Further, after the toner image formed by the developing device is transferred to the transfer paper, the blade (5) is used to transfer the toner image to the photoreceptor drum (1).
), the toner and carrier scraped off by the blade (5) gradually accumulate in front of the blade edge (6), and when the amount exceeds a certain level, the blade removes the toner and carrier. Etsuji (
6), falls along the upper surface of the blade (5) into a spiral portion (see Figure 4aX), and is discharged into a collection bottle (not shown).

Hereinafter, the photoreceptor drum (1) is removed by the blade (5).
A side seal mechanism for preventing toner etc. scraped from the surface of the blade (5) from scattering from both ends of the blade (5) will be described.

In FIG. 2, (13) and (14) are support frames, which both represent hollow portions (S) at both ends of the photoreceptor drum (1).
) of the photoreceptor drum (1).
) in parallel with the drive shaft (3).

In addition, the support frame (14) is provided with support plates (14a) and (14b) parallel to the other support frame (13), and these support plates (14a) and (14b) have a shaft ( 8) is rotatably mounted.

Further, the space between the support plates (14a) and (14a) of the shaft (8) is in contact with the inner surface of the photoreceptor drum (1).
) and a friction roller (7) that rotates driven by the shaft (8).
A worm (9) is attached to the inwardly protruding part.

The support frames (13) and (14) have shafts (12) at their tips.
) is rotatably attached to this shaft (12), and a magnetic roller (11) that faces both ends of the blade edge (6) with a circular drum (1a) in between, and the worm (9).
) and a worm wheel (10) that meshes with the worm wheel (10) is attached.

In addition, as shown in FIG. 3, the magnetic roller (11) is made of a magnet (with S and N poles located on the outer periphery around the spindle (8)).
11a) and (1lb) are provided alternately.

The side seal mechanism configured as described above has a photoconductor drum (
1), the friction roller (7) rotates in the direction of arrow (b), and this rotational force is transmitted to the worm (9) via the shaft (8), and the worm wheel (10) meshes with the worm (9). When rotates in the direction of arrow (C), the shaft (12
), the magnetic roller (11) rotates in the same direction.

By the above operation, a magnetic conveying force is generated at both ends of the blade edge (6) to convey the magnetic material toward the center along the blade edge (6).

For this reason, the blade (5) is removed from the surface of the photoreceptor drum.
and is further deposited on the edge (6),
The toner moving toward both ends of the blade (5) is remixed with the carrier in front of the edge (6) and triboelectrically charged, and when it reaches both ends of the blade (5), it is charged by the magnetic roller (11). The scattering from the end of the blade (5) is prevented by the magnetic transport action in the direction of arrow (d).

Then, the toner that has accumulated in front of the blade edge (6) in excess of a certain amount climbs over the blade edge (6) and moves to the blade (5).
It is collected into a collection bottle along the upper surface of the container via a spiral (4a) shown in FIG.

In the above embodiment, the hollow portions (S) at both ends of the photoreceptor drum (1) are
) is provided with a friction roller (7) that contacts the inner surface of the photoreceptor drum (1) and rotates following the photoreceptor drum (1), and the rotational force of the friction roller (7) is transferred to the worm (9) and the worm wheel ( 10) is transmitted to the magnetic roller (11) via the worm gear, but the present invention is not limited to this.
A drive source for the magnetic roller (11) may be provided separately.

Further, in the above embodiment, by using a predetermined amount of toner and carrier in the developer and adjusting the bias voltage applied to the developing sleeve and the exposure amount,
Forcibly attach the carrier onto the photoreceptor drum (1),
By mixing the toner deposited in front of the blade edge (6) with carrier and triboelectrically charging it, the magnetic roller (1)
2), but since there is usually some carrier on the surface of the photoreceptor drum (1), it is not necessary to set the bias voltage and exposure amount as in the above embodiment. , it is possible to obtain the same effects as in the above embodiment.

Furthermore, the number of rotations of the magnetic roller (12) depends on the size of the friction roller (7) and the worm gear (worm (9)).

It can be adjusted arbitrarily by changing the pitch and size of the teeth of the worm wheel (10).
) can also be set arbitrarily.

(Effects of the Invention) As is clear from the above description, the sideknoll mechanism in the cleaning device according to the present invention has a magnetic roller that is placed in the hollow portions at both ends of the photoconductor drum and facing the blade edge of the cleaning device via the photoconductor drum. is rotatably driven, and the toner scraped off the surface of the photoreceptor and deposited on the blade edge is moved toward the center of the blade, thereby preventing the toner from scattering from both ends of the blade.

Therefore, toner scattering can be reliably and stably prevented over a long period of time, making it possible to significantly lengthen the maintenance cycle for cleaning the inside of the machine, making maintenance management easier and improving machine reliability. do.

In addition, toner scatters and adheres to the corona wire of the charger, etc.
Clear and stable copied images can always be obtained without causing charging defects or copying defects.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the side seal mechanism of the cleaning device according to the present invention, FIG. 2 is a partially cutaway plan view of the photoreceptor drum, FIG. 3 is a cross-sectional view of the magnetic roller, and FIG. FIG. 5 is a cross-sectional view of the cleaning device and a perspective view showing the flow of toner at the blade edge portion. l...photosensitive drum, 2...flange, 3...
... Drive shaft, 4... Blade, 5...
Blade edge portion, 7... Friction roller, 9... Worm, 10... Worm wheel, 11 - Magnetic roller, 13... Support frame, S... Hollow part. Patent applicant Minolta Camera Co., Ltd. Agent
Patent attorney Aoyama Ao and 2 others No. 4v4

Claims (1)

[Claims] (1) A side seal mechanism of a cleaning device in an electrophotographic copying machine, etc., which scrapes off the magnetic developer remaining on the surface of the electrostatic latent image carrier after transfer with the edge of the blade that presses against the electrostatic latent image carrier. A hollow portion formed at both ends of the electrostatic latent image carrier, an axis perpendicular to a rotation axis of the electrostatic latent image carrier at a position facing both ends of the blade edge of the hollow portion, and a peripheral A magnetic roller having S and N poles sequentially magnetized in a direction, and a driving means for rotating the magnetic roller in a direction in which the magnetic roller moves developer toward the center of the blade. side seal mechanism of the cleaning device.