JPH0473590B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing/cleaning device for an electronic copying machine or the like using a magnetic toner monocomponent developer.

FIG. 1 shows an example of a developing/cleaning device in a conventional electronic copying machine. In this electronic copying machine, charging, exposure, development, and transfer steps are sequentially performed during one rotation of the photosensitive drum 1, and a cleaning step is performed during the next rotation. Photosensitive drum 1
A developing device 2 is provided near the. The developing device 2 includes a storage container 4 containing magnetic toner 3;
A magnet roll 5 provided inside this,
A sleeve 6 rotatably provided on the outer periphery of this
and a blade 7 provided near this. One end of an arm 9 is rotatably attached to the shaft 8 of the magnet roll 5. A conductive fur brush (cleaning auxiliary member) 1 is connected to the other end of the arm 9 via a shaft 10.
1 is rotatably provided. The arm 9 is biased counterclockwise in FIG. 1 by a compression spring 12. The other end of the arm 9 is connected to a plunger 15 of an electromagnetic solenoid 14 via a rod 13.

When developing is performed in this apparatus, the electromagnetic solenoid 14 is energized and the plunger 15 is attracted. Then, the arm 9 is rotated clockwise in FIG. 1 against the force of the compression spring 12, and the fur brush 11 is separated from the photosensitive drum 1. When the photosensitive drum 1 rotates in the direction of the arrow in this state, the electrostatic latent image formed on its surface is developed with the magnetic toner 3. That is, a layer of magnetic toner 3 is formed with a constant thickness on the surface of the sleeve 6 rotating in the direction of the arrow by the action of the blade 7. This magnetic toner 3 is produced by the electrical attractive force between it and the electrostatic latent image overcoming the magnetic force by the magnet roll 5 at the main pole of the magnet roll 5 (near the vicinity of the photoreceptor drum 1). It adheres to the electrostatic latent image and is developed.

When cleaning is performed, power to the electromagnetic solenoid 14 is cut off. Then, the arm 9 is rotated counterclockwise in FIG. 1 by the force of the compression spring 12, and the fur brush 11 bites into contact with the photoreceptor drum 1. When the photosensitive drum 1 rotates in the direction of the arrow in this state, the magnetic toner 3 remaining on the surface of the photosensitive drum 1 is cleaned. That is, the residual magnetic toner 3 comes into contact with the fur brush 11 to be neutralized, and its electrical adhesion to the photosensitive drum 1 is weakened. Then residual magnetic toner 3
A part of it is sucked into the fur brush 11 and removed. The remaining magnetic toner 3 is transferred to the magnet roll 5.
is attracted and removed by the magnetic force.

By the way, in such an apparatus, if the fur brush 11 comes into contact with the photoreceptor drum 1 during the phenomenon process, the electrostatic latent image will be disturbed, so in order to avoid this, it is necessary to make the fur brush 11 move toward and away from the photoreceptor drum 1. There is. For this purpose, a contact/separation device consisting of an electromagnetic solenoid 14, a compression spring 12, etc. is used. Therefore, the structure is complicated and large, the weight is large, and the cost is also increased.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a phenomenon and cleaning device that has a simple configuration and can be made smaller, lighter, and lower in cost.

In the present invention, a one-component developer of magnetic toner is used, and during the first rotation of the photoreceptor drum, the latent image on the photoreceptor drum is developed by a developing means consisting of a magnet roll and a sleeve provided on the outer periphery of the magnet roll. In a developing/cleaning device that performs a developing cycle in which the photosensitive drum is cleaned by a conductive cleaning auxiliary member and the developing means in the next rotation, the cleaning auxiliary member has the photosensitive drum on a part of its outer periphery. The conductive cleaning member has a conductive cleaning member in contact with the photoreceptor drum, and the cleaning auxiliary member is rotatably provided at a fixed position, and during the development cycle, the conductive cleaning material is applied to the latent image formed on the photoreceptor drum. In order to achieve the above-mentioned purpose, the above purpose is achieved.

The present invention will be explained in detail with reference to Examples below.

FIG. 2, in which the same parts as in FIG. 1 are given the same reference numerals, shows a developing/cleaning device in one embodiment of the present invention. The conductive fur brush (cleaning auxiliary member) 21 of this device has a structure in which conductive fibers (cleaning material) 23 are provided in a fan shape (approximately semicircular) on a part of the outer periphery of a shaft 22. This fur brush 21 is rotatably provided at a fixed position via a shaft 22. In other words, when the fur brush 21 rotates,
The tip of the fiber 23 is provided at a position where it comes into contact with the photoreceptor drum 1 so as to bite into it. It is desirable that the resistance of the fibers 23 is about 10 to 10 ¹⁰ Ωm, preferably about 10 ⁴ to 10 ⁶ Ωm. The length, thickness, and density of the fibers 23 are preferably about 3 to 10 mm, 3 to 10 denier, and about 10,000 fibers/inch ² to 200,000 fibers/inch ^2, respectively. Also, the photosensitive drum 1 of the fiber 23
It is desirable that the amount of intrusion is about 1 mm. The fur brush 21 rotates once in the direction of the arrow while the photosensitive drum 1 rotates twice in the direction of the arrow. As a method for this rotation, for example, when both are rotated by the same motor via a belt, a method can be considered in which each reduction ratio is made different by a fixed ratio.

In this apparatus, when the photoreceptor drum 1 first rotates once in the direction of the arrow, the electrostatic latent image formed in the exposure process moves together with the photoreceptor drum 1. When the tip of the electrostatic latent image comes to a position facing the fur brush 21, the rear end A of the fur brush 21 rotating in the direction of the arrow is at a position B slightly away from the photoreceptor drum 1.
It is in. Therefore, when the electrostatic latent image passes through a location facing the fur brush 21, the fur brush 21 rotates in the direction of the arrow while being separated from the photoreceptor drum 1. Therefore, the electrostatic latent image is the fur brush 2.
1 will not be disturbed. After this, photosensitive drum 1
According to the rotation in the direction of the arrow, the development and transfer steps are sequentially performed as in the conventional case. In the developing step, it is sufficient that at least one of the magnet roll 5 and the sleeve 6 is rotatable.

After the photosensitive drum 1 completes the first rotation, it starts the next rotation.
Assume that the rotation starts and the tip of the magnetic toner 3 remaining on the surface of the brush comes slightly before facing the fur brush 21. At this time, the front end C of the fur brush 21 rotating in the direction of the arrow is at a position D where it begins to come into contact with the photosensitive drum 1. Therefore, when the residual magnetic toner 3 passes through a portion facing the fur brush 21, the fur brush 21 rotates in the direction of the arrow while slightly biting into the photosensitive drum 1. Therefore, the electrostatic adhesion force of the residual magnetic toner 3 is weakened by contact with the fur brush 21, and cleaning is performed in the same manner as in the conventional method.

In this device, since it is sufficient to simply rotate the fur brush 21, there is no need for a conventional approaching/separating device. Therefore, there is no need to consider the adverse effects of heat generated by the electromagnetic solenoid, and reliability can be improved.

In the above embodiment, the fibers 23 are provided on approximately half of the outer periphery of the shaft 22, but the present invention is not limited to this. For example, as shown in FIG. 3, fibers 31 having a length that does not come into contact with the photosensitive drum 1 may be provided on approximately the remaining half of the outer circumference of the shaft 22. Further, as shown in FIG. 4, the fibers 32 may be provided at a location less than half the circumference of the shaft 22.
Furthermore, as shown in FIG. 5, a substantially semi-cylindrical conductive urethane foam 33 may be used instead of the fibers.

Further, in the above embodiment, the fur brush 21 is rotated once while the photoreceptor drum 1 rotates twice.
It is not limited to this. For example, the fur brush 21 may be switched between contacting the photosensitive drum 1 and not contacting the photosensitive drum 1 by simply rotating the fur brush 21 .

As described above, according to the present invention, it is only necessary to provide the conductive cleaning member in a fixed position so as to be rotatable, so the structure is simple, and it is possible to achieve reductions in size, weight, and cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an example of a conventional developing/cleaning device, FIG. 2 is a schematic side view showing a developing/cleaning device according to an embodiment of the present invention, and FIGS. 3 to 5 are respectively in accordance with the present invention. It is a figure which shows each other Example. 1... Photosensitive drum, 3... Magnetic toner, 5...
... Magnet roll, 6... Sleeve, 7... Blade, 21... Fur brush.

Claims (1)

[Claims] 1. A development cycle in which a magnetic toner monocomponent developer is used to develop the latent image on the photoreceptor drum by a developing means consisting of a magnet roll and a sleeve provided around the outer circumference of the photoreceptor drum during the first rotation of the photoreceptor drum. In a developing/cleaning device that performs a cleaning cycle in which the photoreceptor drum is cleaned by the conductive cleaning auxiliary member and the developing means in the next rotation, the cleaning auxiliary member has a part of its outer periphery that is connected to the photoreceptor drum. It has a conductive cleaning material that comes into contact with it, and the cleaning auxiliary member is rotatably provided in a fixed position, so that the conductive cleaning material does not come into contact with the latent image formed on the photoreceptor drum during the development cycle. A developing and cleaning device characterized by: