JPH0131623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing powder used in an electrostatic copying machine in which an electrostatic latent image formed on a photoreceptor such as a photosensitive drum is developed with magnetic developer powder. The present invention relates to a conveyance device, and more specifically, relates to a conveyance device that is advantageously used, for example, in a cleaning device to convey developer powder removed from a photoreceptor to a storage tank or the like.

In a typical prior art, a fur brush is brought into contact with a photosensitive drum in a cleaning device of an electrostatic copying machine to scrape off toner remaining on the photosensitive drum after transfer. Such prior art has a problem in that the photosensitive drum is easily scratched.

SUMMARY OF THE INVENTION An object of the present invention is to provide a conveyance device that conveys magnetic developer powder using its magnetic force to cut off mechanical contact with a photosensitive drum or the like.

FIG. 1 is an exploded perspective view of one embodiment of the present invention, FIG. 2 is a left side view thereof, and FIG. 3 is a cross-sectional view taken from the cutting plane line - of FIG. 1. A diagram showing the whole in a simplified manner, Figure 4 is the first
It is a sectional view seen from the cutting plane line - of the figure. Referring to these drawings, an exposure device (not shown) is mounted on the photosensitive drum 1 which is rotationally driven in the direction of the arrow 20.
As a result, an electrostatic latent image corresponding to the original is formed.
A one-component magnetic toner adheres to this electrostatic latent image and is developed. The original image developed with toner is transferred to copy paper. The toner remaining on the photosensitive drum 1 in this transferred image is magnetically attracted by the permanent magnet bar 2, and is charged into the storage tank 3 through the inlet 4 and stored therein. Magnetic poles of different magnetism are alternately formed in the permanent magnet bar 2 in its circumferential direction. In this embodiment, eight magnetic poles are formed in the circumferential direction.

The storage tank 3 is made of synthetic resin such as acrylic resin, and can be manufactured by integral molding. The input port 4 of the storage tank 3 extends parallel to the axis of the photosensitive drum 1 when it is attached to the machine body. At the left end of the storage tank 3 in FIG. 1, a recess 5 is formed that is recessed in the longitudinal direction of the storage tank 3 (to the right in FIGS. 1 and 3) near the photosensitive drum 1. A pivot shaft 6 is supported in the storage tank 3 so as to be freely angularly displaceable around its axis. This pivot 6 has an axis along the direction in which the input port 4 extends (that is, the longitudinal direction of the storage tank 3). Axis 6 is
It also includes a portion 6a that extends within the storage tank 3 over the entire length in the longitudinal direction of the storage tank 3, and an end portion 6b that projects outside the storage tank 3. A response plate 7 made of a material such as acrylic resin and extending radially outward of the pivot shaft 6 is fixed to a portion 6a of the pivot shaft 6 within the storage tank 3. This response plate 7 is connected to the input port 4 in the storage tank 3.
over the entire length in the extending direction. The end portion 6b of the pivot 6 is connected to the storage tank 3 in the recess 5 of the storage tank 3.
It sticks out to the outside. This protruding end 6b has
The actuating member 8 is fixed. When the toner is not in contact with the response plate 7, the actuating member 8 comes into contact with the actuator 20 of the micro switch 19, and the response plate 7
forms an angle α (see Figure 2) with the vertical direction. This angle α is determined by the upper surface 7 of the response plate 7 facing the input port 4.
This is the angle at which the toner slides off when it is placed on the surface a.

An oil seal member 9 is provided on the shaft 6 at a portion of the shaft 6 that penetrates the storage tank 3 in order to prevent the toner from leaking out from the storage tank 3 . The actuating member 8 is provided in the recess 5 and does not protrude beyond the end surface 10 of the reservoir 3 . Therefore, there is no possibility that the actuating member 8 will get caught when the storage tank 3 is attached to and detached from the aircraft body. Storage tank 3
A recess 11 is also formed at the other end. The other end 6c of the pivot 6 protrudes from this recess 11, and the end surface of this end 6c does not protrude from the end surface 12 of the storage tank 3, so that the end 6c of the pivot 6
There is no risk that c will be hit or miss.

A stay 13 as a dispensing member made of a high magnetic permeability material such as iron and having a circular cross section perpendicular to the axis is fixed to the body of the copying machine parallel to the axis of one of the photosensitive drums. Engaging portions 14 and 15 formed at the upper part of the storage tank 3 engage with the stay 13 from above. A downwardly facing step surface 25 formed by the end surface 10 and the recess 5 and a downwardly facing step surface 26 formed by the end surface 12 and the recess 11 are supported by the fuselage. In this way, the storage tank 3 is attached to the aircraft body. A micro switch 19 is fixed to the body of the copying machine so that it is located in the recess 5 with the storage tank 3 attached. The actuator 20 of this microswitch 19 faces the side 8a of the actuating member 8 on the photosensitive drum 1 side.
The stepped surface 27 facing the photosensitive drum 1 side formed by the end surface 10 and the recess 5 limits the angular displacement of the actuating member 8 in the clockwise direction in FIGS. 1 to 3.

When toner is charged into the storage tank 3 from the input port 4 and the amount of the stored toner reaches above the axis 6, the toner presses the upper surface 7a of the response plate 7 downward. In this way, a counterclockwise moment as shown in FIGS. 1 to 3 acts on the pivot shaft 6. Therefore, the actuating member 8 presses the actuator 20. In this way, the switching mode of the micro switch 19 is changed, and a lamp is turned on to warn the outside that a large amount of toner has been stored in the storage tank 3. When this alarm is generated, the machine is opened, the storage tank 3 is taken out from the machine, and the toner in the storage tank 3 is thrown away.

The permanent magnet bar 2 has a stainless steel drive shaft 37.
is inserted, and the permanent magnet bar 2 and the drive shaft 37 are fixed. The drive shaft 37 is rotationally driven around its axis.

The process of toner being magnetically attracted from the photosensitive drum 1 by the permanent magnet bar 2 and being charged into the storage tank 3 from the input port 4 of the storage tank 3 is shown in FIG. For example, when the photosensitive drum 1 is moved in the direction of the arrow 20,
It rotates at 40 rpm, and the photosensitive drum 1 is attached to the permanent magnet bar 2.
It is rotated at 200 to 300 rpm, for example, in the direction of arrow 21 so as to be in the opposite direction on the side surface. The toner remaining after transfer on the photosensitive drum 1 is indicated by reference numeral 30. This toner 30 is attracted to the surface of the permanent magnet bar 2 by the magnetic force of the permanent magnet bar 2, and becomes a spike-shaped toner 31. The attracted toner 31 is brought to the storage tank 3 side as the permanent magnet bar 2 rotates in the direction of the arrow 21. Toner 31 attached to permanent magnet bar 2
is scraped off by the blade 22 fixed to the fuselage, and the stay 1 made of high magnetic permeability material
It is magnetically attracted to the outer peripheral surface of 3. As the permanent magnet bar 2 rotates in the rotational direction 21, the toner 39 adsorbed on the stay 13 jumps into the storage tank 3 from the input port 4.

The inventor of the present invention has investigated the reason why the toner jumps from the stay 13 into the storage tank 3 as follows. Referring to FIG. 6 1, stay 1
The N pole 3 of the permanent magnet bar 2 is on the permanent magnet bar 2 side of 3.
8 are close to each other, an S pole 32 is formed, and an N pole 33 is formed on the opposite side of the stay 13. The magnetic flux density is high near the north pole 38 of the permanent magnet bar 2, and the magnetized area of the south pole 32 of the stay 13 is smaller than that of the north pole 33.

The permanent magnet bar 2 rotates in the direction of the arrow 21 to
As the state shown in FIG. 2 is reached, the magnetic pole of the stay 13 changes as shown in FIG. 6, FIG. 2. As the magnetic poles 32 and 33 formed on the stay 13 move in this manner, the toner 39 on the outer peripheral surface of the stay moves toward the storage tank 3 side.

Next, when the permanent magnet bar 2 further rotates and reaches the state shown in FIG. 6, and the magnetic pole on the stay 13 side becomes the S pole 40, the area of the N pole 33 of the stay 13 is small, The area becomes larger. In the S pole 32 having a large area, the magnetic attraction force per unit area of the outer surface of the stay 13 is weak. Therefore, the toner 39 in the area of the S pole 32 falls due to its own weight and is discharged from the stay 13.
Jump into storage tank 3. Further, at this time, the inertial force of the toner 39 caused by the rotation of the permanent magnet bar 2 also makes it easier for the toner 39 to separate from the stay 13 .

In the above-described embodiment of the invention, blade 2
2, the residual toner can be temporarily stopped by the sliding contact between the blade 22 and the permanent magnet bar 22, and the remaining toner can be transferred to the stay 13. Although the magnetic brush does not need to be formed and transferred to ensure reliable ablation, in other embodiments, the blade 22 may not be attached.

In the present invention, the developing powder can be applied not only to one-component toner but also to two-component toner.

As another embodiment of the present invention, a sleeve made of a low magnetic permeability material such as aluminum or stainless steel may be fixed to the body around the outer periphery of the permanent magnet bar 2 that is driven to rotate. In addition, the outer peripheral surface of the permanent magnet bar 2 is closely covered with a tube made of a synthetic resin material, or is coated with a synthetic resin to improve the slippage of the toner 31.
It may be made easier to transfer from the side to the stay 13. Furthermore, due to such a synthetic resin layer, the toner 31
is electrically isolated from the permanent magnet bar 2, and the toner 3 of the permanent magnet bar 2 is released regardless of the electrostatic force.
1 is easily attracted to the stay 13.

The present invention can also be implemented to convey developer powder from a developer powder supply hopper to a permanent magnet for making a magnetic brush face a photoreceptor such as a photoreceptor drum in a magnetic brush developing device of an electrostatic copying machine. can do.

Instead of the permanent magnet bar 2, the magnetic field may be formed by an electromagnet. In the illustrated embodiment,
Although the stay 13 as a dispensing member also has the function of supporting the storage tank 3, it is needless to say that it does not have to have such a function according to the present invention.

As described above, according to the present invention, developer powder is adsorbed by the developer powder adsorbing means consisting of a magnet driven to rotate about an axis, and the developer powder on the surface of the magnet is discharged from the dispensing member. Therefore, the developer powder can be transported without eliminating mechanical contact with a developer powder supply source such as a photosensitive drum.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of an embodiment of the present invention, FIG. 2 is a left side view of the storage tank 3 in FIG. 1, and FIG. 3 is a sectional view taken from the cutting plane line - in FIG. FIG. 4 is a sectional view taken from the cutting plane line - in FIG. is the toner 3 related to the permanent magnet bar 2 and the stay 13.
1 and 39 are simplified side views for explaining the moving state. 1...Photosensitive drum, 2...Permanent magnetic bar, 3...
Storage tank, 4... Input port, 6... Pivot, 7... Response plate, 8... Operating member, 13... Stay, 19...
Micro switch.

Claims (1)

[Scope of Claims] 1. A developer powder adsorption means consisting of a magnet having a plurality of magnetic poles in the circumferential direction and rotationally driven around an axis, and a developer powder adsorption means parallel to the developer powder adsorption means and within the magnetic field of the developer powder adsorption means. What is claimed is: 1. A developing powder conveying device comprising: a dispensing section made of a high magnetic permeability material and disposed at intervals. 2. The developer powder adsorption means according to claim 1, wherein the developer powder adsorption means has a structure in which a sleeve made of a low magnetic permeability material is fixedly provided around the outer periphery of a rotationally driven magnet. Device. 3. The developer powder conveying device according to claim 1, wherein the developer powder adsorption means is constructed by forming a synthetic resin layer on the outer peripheral surface of a rotationally driven magnet.