JPH0235984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner cloud prevention device in an electrophotographic copying machine or the like.

As shown in FIG. 1, in a conventional device of this kind, a suction port 4 of a suction section 3 provided at the bottom of a developing device 2 disposed around one periphery of a photoreceptor drum 1 is arranged in the direction of one periphery of the photoreceptor drum 1. Because the toner cloud was formed in the direction of the photosensitive drum 1, it was not possible to suck up all the toner cloud that was generated inside the developing machine 2 and was about to scatter outside the developing machine 2, and some of it was scattered on the surface of the photoreceptor drum 1. The problem is that the suction port 4 of the suction section 3 is configured as shown in FIG. The force is uneven, so the toner cloud sucked from the suction port tends to concentrate in the area where the suction force is strong. Therefore, if a large amount of toner cloud is generated, the toner cloud is sucked from the suction port where the suction force is strong. 4, and this had the disadvantage that it seriously stained the background of both ends on the copy.

The present invention has been made in order to eliminate the drawbacks of the conventional toner cloud prevention device described above, and has the purpose of directing the suction port of the suction section provided at the lower part of the developing machine toward one periphery of the mag roll in the upper developing machine. By arranging the toner cloud, all the toner cloud generated around the mag roll can be sucked into the suction section, and by providing a partition inside the suction port, the toner cloud can be sucked into the suction port. An object of the present invention is to provide a toner cloud prevention device for an electrophotographic copying machine, etc., which has a uniform suction force over the entire surface of a suction port.

The present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 3 is a schematic diagram showing an embodiment of the toner cloud prevention device of the present invention.

A developing device 6 is arranged around one area of the photoreceptor 5. The developing device 6 includes a paddle wheel 8, a cross mixing plate 9, a mag roll 10, a trimmer plate 11, etc. along a developer conveyance path from a blender 7 disposed in a developer reservoir to one periphery of the photoreceptor drum 5. Each is placed in its proper place. A suction portion 12 connected to an air filter (not shown) is provided at the lower part of the developing device 6, and a suction port 13 of the suction portion 12 is connected to the developing device 6 provided close to one periphery of the photoreceptor drum 5. The suction port 13 is disposed toward one periphery of the lower surface of the inner mag roll 10, and a partition 14 is disposed at an appropriate position inside the suction port 13, as shown in FIG.

The present invention is constructed as described above. Next, its operation will be explained.

An appropriate amount of toner is sent from a toner container (not shown) via a toner dispenser to a developer reservoir in a developing device 6, where it is frictionally charged by a blender 7 and mixed with a carrier. The toner mixed with the carrier is then picked up from the paddle wheel 8 onto the mag roll 10 after the toner content is made uniform in the axial direction by the cross mixing plate 9. The Magroll 1
The toner picked up on the photoreceptor drum 5 is conveyed to the electrostatic latent image on the photoreceptor drum 5 with the amount of developer controlled to an appropriate amount by the trimmer plate 11. In this process, a toner cloud is generated when the toner is stirred and conveyed in the developing device 6 by the blender 7, paddle wheel 8, mag roll 10, etc. Then, the toner cloud is transferred to the suction port 1 of the suction section 12 provided at the lower part of the developing device 6.
Since the suction port 13 is oriented toward one periphery of the lower surface of the mag roll 10 as described above, the toner cloud is successively sucked by the mag roll 10. All of the air is sucked into the suction section 12 from around the suction port 13, and is sucked into the air filter under negative pressure. When this toner cloud is sucked from the suction port 13 into the suction unit 12, a partition 14 is placed at an appropriate position within the suction port 13, and the suction force of the air is applied to the entire surface of the suction port 13. Since the toner cloud is configured to be uniform, the toner cloud is formed at the suction port 13,
The suction is uniformly distributed over the entire surface without being concentrated at both ends.

The present invention is configured and operates as described above. Conventionally, the suction port of the suction section was arranged toward one periphery of the photoreceptor drum. This has the effect of almost completely preventing a part of the toner cloud from being scattered onto the surface of the photoreceptor drum. ,
By arranging an appropriate number of partitions 14 at appropriate locations inside, the suction force of the air from the locations is made uniform over the entire surface of the suction port 13, so that the toner cloud is Suction port 13
The suction is not concentrated at both ends of the copy, and therefore, it is almost completely possible to prevent the background from being severely stained at both ends of the copy, which conventionally occurs due to this concentrated suction, and to ensure high-quality copies at all times. It also has the effect of being able to provide the following.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional developing machine, FIG. 2 is an enlarged cross-sectional view taken along the line A-A in FIG. 1, FIG. 3 is a schematic diagram of a developing machine of the present invention, and FIG. It is a BB line cross-sectional enlarged view of. In the figure, 5...photosensitive drum, 6...developing machine, 10
...Maglor, 12...Sakusion Club, 13...
...Suction port, 14...Partition.

Claims (1)

[Claims] 1. The direction of the suction port of the suction section provided at the bottom of the developing machine located around one area of the photoreceptor is oriented toward the periphery of the bottom of the mag roll in the developing machine located above the suction port, and the inside of the suction port is 1. A toner cloud prevention device for an electrophotographic copying machine, etc., characterized in that a proper number of partitions are arranged at appropriate locations in the toner cloud to ensure uniform suction force over the front surface of the suction port.