JPS59129881A - Magnetic brush developing device of electrostatic copying machine - Google Patents

Abstract

PURPOSE:To carry sufficiently by a two component developer degraded in fluidity employing even a small particle diameter carrier, by forming a bucket structure of a bucket wheel by an L-shaped bucket bridged laterally on a pair of flanges. CONSTITUTION:A developing roll 20 and a bucket wheel 23 are provided in a developing vessel 27, and plural pieces of buckets consisting of a lateral piece 231a and a longitudinal piece 231b, and having an L-shaped section are bridged laterally at equal intervals in the rotating direction, on a pair of circular fanges 232 of the left and right of the wheel 23. A developer 24 is scooped by this bucket 231, carried to a developer adsorbing position 21 and adsorbed. Therefore, even if a two component developer whose fluidity is bad by using a small particle diameter carrier is used, the developer goes smoothly into the bucket, and the developer can be carried and fed enough to the developing roll 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention 1 relates to a magnetic brush developing device for an electrostatic copying machine.

Conventionally, a magnetic brush developing device for an electrostatic copying machine is provided with a footwheel 4, the packet wheel 4 transports the developer 6 in the developer reservoir 5 to the developing roll 3, and the developing roll 3 absorbs and transports the developer. An apparatus is known in which an image on a photoreceptor 2 is developed using a photoreceptor.

However, with this device, the packet wheel 4 has a structure in which a plurality of packets 8 with a concave cross section are horizontally fixed across a pair of flanges 7 and 7 with gaps in the rotation direction. When using a two-component developer using a diameter carrier, due to the poor fluidity of the two-component developer,
There is a problem that the developer cannot enter into the packet 8 and the developer cannot be sufficiently conveyed to the developing roll 3.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to prevent the developer from remaining in the packet even when a developer with poor fluidity such as a two-component developer using a small particle carrier is used. To provide a magnetic brush developing device for an electrostatic copying machine which can smoothly enter and sufficiently convey developer to a developing roll.

The present invention will be described in detail below with reference to FIG. 2 and subsequent figures.

A developing roller 20 and a packet wheel 23 are provided in a developing container 27 provided opposite to the photoreceptor 19 .

The developing roll 20 includes an internally fixed magnet 20+ and a non-magnetic cylinder 204 that rotates around the outer periphery of the internally fixed magnet 201 in the direction of an arrow 203, and faces the photoreceptor 19 from the opening 272 of the developing container 27. . 205 is a support shaft. Although the internal fixed magnet 201 is a cylindrical magnet, a rectangular parallelepiped anisotropic magnet may be arranged.

The packet wheel 23 straddles a pair of left and right circular flanges 232 rotatably supported by a support shaft 233, and has a horizontal piece 231a.
It has a structure in which a plurality of L-shaped packets 231 having an L-shaped cross section with a vertical piece 231b are horizontally fixed at equal intervals in the rotational direction so that the vertical pieces 231b are on the rear side in the rotational direction,
There is a gap 23 between adjacent L-shaped packets 231 and 231.
5 is formed and the circular 7 flange 232 is rotated in the direction of arrow 234.

Reference numeral 25 denotes a stirring device, which is provided in a path where the developer 24 returns to the developer reservoir 271 of the developer container 27, and stirs the developer 24 in a direction parallel to the spindle 205 (hereinafter referred to as the axial direction). be.

The stirrer W25 is provided with a pair of augers 251 and 252 that rotate in opposite directions and are parallel to the support shaft 205.

26 is a toner replenishment mechanism installed above the stirring w25,
As shown in FIG.
The screw conveyor 263 has a structure in which a notch 261 is spirally cut into the tube 262, and a screw conveyor 263 is a bar-shaped metal or resin wound with strips or wires in a spiral shape.

2g is a regulation plate that controls the amount of developer adsorbed by the developing roll 20, and 29 is a peeling plate that peels off the developer from the developing roll 20 after development.

Next, the operation will be explained.

The developer 24 is scooped into the horizontal piece 23;
By rotational movement in 34 directions, the developer is transported to the developer adsorption position 21 of the developing roll 20 and adsorbed onto the developing roll 20 .

Thereafter, the developing roll 20 is conveyed to the developing area 30 by rotational movement in the direction of the arrow 203, and the image on the photoreceptor 19 is developed.

The developer that has completed development is peeled off by the peeling plate 29 and falls into the developer reservoir 271.

On the way, the support shaft 2 is moved by a pair of augers 251 and 252.
The mixture is stirred in a direction parallel to 05.

At the same time, the toner dropped from the toner supply mechanism 26 is stirred and mixed with the developer by the augers 251 and 252.

As described above, since the developer 24 is scooped up by the horizontal piece 231a and the vertical piece 231b of the L-shaped packet 231,
Even when a developer with poor fluidity such as a two-component developer using a small particle carrier is used, the developer can smoothly enter the packet 231 and can be sufficiently conveyed to the developing roll 20.

The toner replenishing mechanism 26 is one in which toner is conveyed from a toner storage box (not shown) by a conveying body 264 such as a screw conveyor or bead chain, and the toner is uniformly dropped and supplied in the axial direction through a spiral cut 261. It is.

Since the present invention is configured as described above, even when a developer with poor fluidity such as a two-component developer using a small particle carrier is used, the developer smoothly enters into the packet 231 and the developer is removed. It can be sufficiently transported to the developing roll 20.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional example, FIG. 2 is a perspective view showing an embodiment of the present invention, FIG. 3 is a sectional view thereof, and FIG. 4 is a perspective view of a toner supply mechanism. 19 is a photoreceptor, 20 is a developing roll, 21 is a developer adsorption position, 23 is a packet wheel, 24 is a developer, 30 is a developing area, 231 is an L-shaped packet, 232 is a 7-lunge,
271 is a developer reservoir. Figure 1 @ Figure 3 t1 Figure 4

Claims (1)

[Claims] A developing roll 2o is disposed in the developing container 27, which absorbs and conveys the developer 24, and supplies it to the developing area 30 to develop the image on the photoreceptor 19.
4 is the developer adsorption position of the developing roll 2o! In a magnetic brush developing device equipped with a backing hole 23 for conveying up to 2+, the packet wheel 23 is connected to a pair of flanges 2
2. A magnetic brush developing device for an electrostatic copying machine, characterized in that a plurality of L-shaped packets 231 are horizontally fixed at intervals in the rotational direction astride L-shaped packets 32 and 232.