JPS6230433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnet roll used in a magnetic brush developing device or a magnetic brush cleaner device.

Generally, in PPC type electronic copying apparatuses, a system using magnetic toner is being adopted because it has many advantages such as no need to control toner concentration, is maintenance free, and simplifies the process. The copying process in this case is as follows. A rotating drum made of an optical semiconductor such as selenium is charged in a dark place.
Exposure is performed to form an electrostatic latent image on the drum surface. Next, magnetic brush development is performed using magnetic toner in a developing device to make an image visible, and then the toner image on the drum is transferred to general paper by an appropriate means such as corona transfer at a transfer position, and then the toner image is transferred to general paper by pressure or A copy is completed through a heat fusing process. Further, the photosensitive drum is cleaned of residual toner that has not been transferred by a cleaning mechanism and is reused.

In the developing device used in the above-mentioned PPC type electronic copying apparatus, in order to obtain a good image, a dual rotation type in which the permanent magnet member is rotated at high speed and the sleeve is rotated at low speed is advantageous because developing performance is improved. For example, if the circumferential speed of the photoreceptor is 150 mm/sec, the permanent magnet member should rotate at about 1400 rpm, while the sleeve should rotate at about 1400 rpm.
It is necessary to rotate at a rotation speed of 100r.pm or less. Also, in the magnetic brush cleaner device,
Similarly, it is more efficient to rotate the permanent magnet member at high speed and rotate the sleeve at low speed.

Generally, in the developing device and cleaner device used in PPC type electronic copying devices, when the rotation speed of the sleeve exceeds 1/5 of the rotation speed of the permanent magnet member, the toner conveyance speed is too fast and the image becomes hard. This causes a number of problems, such as deterioration of the toner, increased scattering of the toner, and excessive force acting on the toner due to the strong toner conveyance force, which causes deterioration of the quality of the toner containing a considerable amount of resin. In this case, the rotation speed of the sleeve is equal to the rotation speed of the permanent magnet member.
More preferably, it is 1/10 or less.

However, in conventional magnet roll drive systems, in order to obtain a large reduction ratio, the permanent magnet member and the sleeve are rotated by separate drive sources (motors) (for example, see Utility Model Application No. 52-70452), or gears, etc. It is common to perform several stages of deceleration. However, this type of system has disadvantages such as an increase in the size of the device and a complicated mechanism.

An object of the present invention is to provide a magnet roll that has a simple mechanism and can obtain a large reduction ratio.

The details of the present invention will be explained based on the drawings showing examples. FIG. 1 is a sectional view of a magnetic brush cleaner device using a magnet roll of the present invention, FIG. 2 is a view taken along arrow A--A in FIG. 1, and FIG. 3 is a view taken along B-- in FIG.
A view taken along arrow B and FIG. 4 is a sectional view taken along line CC in FIG. The magnet roll 1 has a structure in which a permanent magnet member 3, which is formed by fixing a cylindrical permanent magnet 3b to the outer periphery of a rotating shaft 3a, is supported via a bearing 4 in a non-magnetic sleeve 2 made of Al, SUS, etc. There is. A spur gear 5 is fixed to one end of the rotating shaft 3a of the permanent magnet member 3. Further, a flange 7 attached to one end of the sleeve 2 is supported by a side plate 10 via a bearing 6. On the other hand, a roller clutch 8 that rotates in only one direction is press-fitted into a flange 7' attached to the other end of the sleeve 2 so as to be positioned concentrically with the rotating shaft 3a. A shaft 9a fixed to a swing plate 9 is fitted into the roller clutch 8. Further, a flange 7' attached to the other end of the sleeve 2 is supported by a side plate 10' via a bearing 6'. A drive shaft 11 is provided above the magnet roll 1. One end of the drive shaft 11 is supported by the side plate 10 via a bearing 14. A gear 13 is fixed to one end of the drive shaft 11, and the gear 13 meshes with a spur gear 12 that meshes with the gear 5. Note that one end of the drive shaft 11 is pivotally supported by a main body side plate 19 by means not shown. The other end of the drive shaft 11 is a pin 16
is connected to an eccentric cam 15 that engages with the swing plate 9. The eccentric cam 15 is supported by the side plate 10' via a bearing 14'. Also, eccentric cam 15
is connected by a pin 17 to a main body side drive shaft 18 supported by a main body side plate 19' and rotated by a drive source (not shown) such as a motor.

In addition, in FIG. 4, 22 is a photosensitive drum;
20 is a scraping plate, and 21 is a toner container. Further, in FIG. 4, parts such as the eccentric cam 15 are omitted for easy understanding.

The operation of the magnetic brush cleaner device shown in FIGS. 1 to 4 will be explained. When the drive source on the main body side is activated to rotate the main body side drive shaft 18 counterclockwise when viewed from the B-B direction, the drive shaft 11 rotates counterclockwise as shown in FIG. rotates counterclockwise via spur gear 12. Therefore, the permanent magnet member rotates counterclockwise. On the other hand, the second
As shown in the figure, as the drive shaft 18 rotates, the eccentric cam 15 also rotates, and the swing plate 9 performs a swing motion with a constant amplitude as shown by the arrow. Since the movement of the rocking plate 9 is transmitted to the sleeve 2 via the roller clutch 8, the sleeve 2 rotates once while the permanent magnet member 3 rotates several times. That is, the sleeve 2 can rotate at a lower rotational speed than the permanent magnet member 3. In this case, the rotation direction of the roller clutch 8 is counterclockwise when viewed from the AA direction, and the rotation of the shaft 9a is transmitted to the flange 7'.
On the other hand, if the roller clutch 8 is set so that the shaft 9a rotates idly during clockwise rotation, the sleeve 2 will rotate in the opposite direction to the permanent magnet member 3. It is also possible to rotate the sleeve and magnet in the same direction by reversing the operating direction of the roller clutch. In this way, in the present invention, by providing a driving means including an eccentric cam, a roller clutch, and a swing plate, the number of rotations of the sleeve can be made lower than the number of rotations of the permanent magnet member, and the amplitude of the swing plate can be adjusted appropriately. By setting, the ratio (reduction ratio) between the rotation speed of the sleeve and the rotation speed of the permanent magnet member can be adjusted to a predetermined value.

As is clear from the above explanation, in the magnet roll of the present invention, the amplitude of the oscillating plate can be adjusted by the dimensions of the eccentric cam and the oscillating plate, so by appropriately selecting these, the reduction ratio can be adjusted. It can be set steplessly to a predetermined value.

In the case of FIG. 4, by rotating the magnet 3 and sleeve 2 as shown, the photosensitive drum 2
This is a magnetic brush cleaner device in which toner (not shown) remaining on the sleeve 2 is continuously adsorbed onto the sleeve, and the toner conveyed on the sleeve 2 is scraped off by a scraping plate 20 and stored in a toner container 21. .

FIGS. 5 and 6 are other embodiments of the present invention in which the speed reduction mechanism is processed only on one side. FIG. 5 is a sectional view of a magnetic brush cleaner device using the magnet roll of the present invention, and FIG.
It is a view from arrow D. In both figures, the same functional parts as in FIGS. 1 to 4 are designated by the same reference numerals.

A spur gear 5 is fixed to an end of the rotating shaft 3a. Flange 7' attached to the end of sleeve 2
is supported by the side plate 10' via a bearing 6'.
The side plate 10' is fixed to the main body side plate 19'.
A roller clutch 8 press-fitted into the rocking plate 9 is fitted onto the end of the flange 7'. Also side plate 1
0', a shaft 23 is supported via a bearing (not shown). An eccentric cam 15 that engages with the swing plate 9 and a spur gear 13 that meshes with the spur gear 5 are fixed to the shaft 23 .

The operation of this device will be explained. A high-speed rotating drive source (not shown) is activated to rotate the spur gear 5 via a suitable transmission mechanism. The spur gear 5 is the rotating shaft 3
Since it is fixed at point a, the permanent magnet member 3 rotates. Further, when the spur gear 5 rotates, the eccentric cam 15 rotates via the spur gear 13. Therefore, the swing plate 9 repeats the swing motion with a constant amplitude as shown by the arrow in FIG. can. In this case as well, the reduction ratio and the direction of rotation of the magnet and sleeve can be adjusted in the same manner as in the case of FIGS. 1 to 4.

According to the present invention, the following effects can be achieved.

(1) Since a single driving source is used and a large reduction ratio can be obtained with a simple mechanism, the magnetic brush developing device and the magnetic brush cleaner device can be downsized.

(2) Since it is possible to obtain a large reduction ratio of 1/5 or less, desired copying conditions can be easily obtained and it is possible to prevent image deterioration, toner scattering, toner deterioration, etc. .

The apparatus of the present invention can be applied not only to the magnetic brush cleaner apparatus as shown in the embodiment, but also to a magnetic brush developing apparatus.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a magnetic brush cleaner device using a magnet roll of the present invention, and Fig. 2 is a sectional view of a magnetic brush cleaner device using a magnet roll of the present invention.
FIG. 3 is a view taken along the line BB in FIG. 1, FIG. 4 is a sectional view taken along C-C in FIG. 1, and FIG. The sectional view shown in FIG. 6 is a view taken along the line DD in FIG. 5. 1: Magnet roll, 2: Sleeve, 3: Permanent magnet member, 3a: Rotating shaft, 8: Roller clutch, 9: Swing plate, 9a: Shaft, 11: Drive shaft, 1
5: Eccentric cam.

Claims (1)

[Scope of Claims] 1. A cylindrical sleeve made of a rotatable non-magnetic material, a permanent magnet member rotatably supported within the sleeve, and a rotational speed of the sleeve. In the magnet roll, the magnet roll includes a driving means for rotating the permanent magnet member so that the number of rotations is 1/5 or less of the rotation speed of the permanent magnet member, the driving means comprising: an eccentric cam that rotates in conjunction with the permanent magnet member; a one-way clutch fitted to one end of the sleeve; and a rocking plate connected concentrically to the sleeve via the one-way clutch and swinging within a constant amplitude due to rotation of the eccentric cam. 1. A magnet roll having an amplitude set such that the number of rotations of the sleeve is 1/5 or less of the number of rotations of the permanent magnet member. 2. The magnet roll according to claim 1, wherein the amplitude of the oscillating plate is set so that the number of rotations of the sleeve is 1/10 or less of the number of rotations of the permanent magnet member.