JPS62194271A - Toner sucking device - Google Patents

Abstract

PURPOSE:To efficiently prevent toner from being scattered with small-sized constitution by arranging the suction port of a toner sucking device nearby both side ends of a developing sleeve. CONSTITUTION:The toner sucking device 3 is fixed under a developing device 2 between side frames 21 and 22, fan motors 25 and 26 are arranged in a casing 23 across a filter 24, and a free end opening parts 33 and 34 of suction duct 31 and 32 are positioned nearby both side ends of the developing sleeve 11. When the developing device 2 is excited, the internal pressure in an upper space area A rises, and air which is blown out nearby both side end parts of the developing sleeve 1 and contains toner is sucked by fan motor 25 and 26 from opening parts 33 and 34. Thus, only air nearly both side ends of the developing sleeve 11 is sucked and the area of the opening parts 33 and 34 and the output of the fan motor may be small. Toner is collected by the filter 24 and clean air is discharged from the device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a toner suction device incorporated into an image forming apparatus such as an electrophotographic copying machine using a two-component developer.

(Prior Art) Generally, in the developing device of an image forming apparatus that uses a two-component developer, toner and carrier are constantly stirred inside, so toner may scatter from the opening and contaminate the inside of the machine, or the charge wire There was a problem that it could accumulate on the surface and cause uneven charging. Therefore, in order to prevent toner scattering, a suction device is known in which a toner suction port is provided along the generatrix direction of a developing sleeve that is disposed so as to close the opening. However, in order to effectively suck the toner through such a large suction port, a fan that sucks in a large amount of air is required, which has the drawback of increasing the size of the toner suction device and, by extension, the developing device. Moreover, since a filter for separating and removing toner is installed in the suction side flow path of the suction device, not only does the suction efficiency deteriorate and the air volume decreases, but also the electrostatic latent image carrier (hereinafter referred to as photoreceptor) There is also the problem that filter replacement is difficult and takes a lot of time because the space is close to each other, and the suction device has to be even larger in order to secure the air volume.

Furthermore, even if an attempt is made to cool the developing device by using exhaust air from the suction device, the suction device will be large and, due to space considerations, separate piping to the developing device will be required, resulting in a complicated structure.

(Objective) The present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object thereof is to provide a toner suction device that is small and can prevent toner scattering. Another object of the present invention is to provide a toner suction device that is compact and can easily replace a filter that separates scattered toner. Still another object of the present invention is to provide a toner suction device that is small and can easily replace a filter that separates scattered toner. An object of the present invention is to provide a toner suction device that can be cooled.

(Structure) The present invention is characterized by the following structure in order to be compact and prevent toner from scattering. In other words, the developing sleeve is arranged at the opening of the developing device and is in contact with the photoreceptor, but since so-called magnetic brushes are formed on the surface of the developing sleeve, the toner flows into the device from both ends of the developing sleeve that do not form magnetic brushes. Focusing on the phenomenon of outward scattering, the inlet of the toner suction device is placed near both ends of the developing sleeve.

Another feature of the present invention is that, in addition to the above structure, the filter is disposed near the outlet of the toner inhaler so that the toner filter can be easily replaced.

Furthermore, in order to cool the developing device, the present invention takes advantage of the miniaturization achieved by the above configuration and arranges the toner suction device near the developing device, and directs at least a portion of the discharged air toward the casing of the developing device. It is characterized by ejecting water.

The illustrated embodiment will be described in detail below. In FIG. 1, reference numeral 1 indicates an electrostatic latent image bearing member, which is called a photoreceptor or a recording member. Hereinafter, it will be referred to as a photoreceptor. Reference numeral 2 indicates a developing device, and reference numeral 3 indicates a toner suction device. The developing device 2 is internally divided into a toner tank 5 and a developing section 6 by a partition plate 4 . A toner cartridge 7 is mounted on the top of the toner tank 5 and drops the toner therein, and the agitator 8 rotates to agitate the toner. 1-The toner in the tank 5 is supplied to the developing section 6 via a toner supply roller 9 that rotates in response to a toner supply signal. The developing section 6 has a paddle wheel 1 at its bottom.
0 is constantly rotated, and a developing sleeve 11 is disposed at the top in such a manner as to close the opening 2a, and the developing sleeve 11
It rotates while facing the In this case, the photoreceptor 1 is rotating counterclockwise in the figure, and the magnetic brush on the developing sleeve 11 is rotating clockwise in the figure.

Now, the toner that has entered the developing section 6 is mixed with the developer, further stirred by the paddle wheel 10, and pumped up and sent to the developing sleeve 11.

The developer (magnetic brush) sent to the developing sleeve 11 is regulated to a constant height by a pre-doctor 12 and a doctor 13. At this time, the excess developer scraped off by the doctor is sent to the separator 14, and when a portion passes through a toner concentration sensor 15, the toner concentration of the developer is detected. The remaining developer is conveyed by the screw 16, and the developer is exchanged in the lateral direction to enhance the stirring effect. Next, the toner suction device 3 will be explained with reference to FIG. 2 as well as this figure. Side frames 21.22 extend laterally from the machine bottom plate 20, and the developing device 2 is movably supported along guide rails 41.4 attached to the upper edges of the side frames 21.22. ing. The toner suction device 3 is located below the developing device 2 and is fixed between the side frames 21 and 22.

That is, the box-shaped casing 23, which is a rectangular parallelepiped, has its bottom surface in contact with the machine bottom plate 20, and its negative side surfaces in contact with the side frame 21. Further, fan motors 25 and 26 are arranged with the internal filter 24 of the casing 23 interposed therebetween. Holes 27 and 28 are bored at both longitudinal ends of the side surface of the casing 23 and the side frame 21, and the holes 27 and 28 are connected to the suction sides of the fan motors 25 and 26 via L-shaped ducts 29 and 30, respectively. connected. Furthermore, suction ducts 31, 32 are connected to these holes 27, 28 (the length is extremely shortened in FIG. 2), and the free end opening 33
．． 34 are located near both ends of the developing sleeve 11. The filter 24 has a rectangular cylinder shape and is made of an electrostatic adsorption material, and has holes 27.2 in the center in the longitudinal direction.
A discharge port 36 is provided on the opposite side of the discharge port 8. Holes 37 and 38 having substantially the same shape as this discharge port 36 are also bored in the casing 23 and the side frame 22 at positions corresponding to the discharge ports 36. The fan motors 25 and 26 suck air in the direction of the arrow, that is, from the opening 33.34, through the suction duct 31.32 and the L-shaped duct 29.30, and the air is sucked into the filter 24.
It is discharged out of the device through the outlet 36 and holes 37 and 38. Further, a cooling hole 39 of an appropriate size is bored in the ceiling of the casing 23.

It has the above configuration. The operation of the toner suction device will be explained. FIG. 3 is an operation timing chart of this apparatus, in which the fan motor is rotated at the same time as the developing device drive motor (developing motor) in synchronization with the input of the print signal. Therefore, there is no need to constantly rotate the fan motor, resulting in low noise, and the life of the motor is extended, resulting in high reliability. Now, in FIGS. 1 and 2, when the developing device 2 is energized, the developing device 2
The internal pressure in the upper space area A increases. However, since a magnetic brush is formed between the central portion of the developing sleeve 11 and the photoreceptor 1, the air cannot flow out and is blown out near both side ends of the developing sleeve 11. The blown air containing toner is
The air is sucked through the openings 33 and 34 via the fan motors 25 and 26. In this way, since it is necessary to suck only the air near both side ends of the developing sleeve 11, the area of the openings 33 and 34 and the output of the fan motor can be small. Therefore, the toner suction device 3 is small-sized, can be stored in the lower part of the developing device 2, and is detachably attached to the machine.

The toner passes through the fan motor 25, 26 and filter 2.
4, and combined with the electrostatic adsorption function, it is efficiently collected. Since the filter 24 is placed on the exhaust side of the fan motor 25, 26, there is no need to consider the adhesion between the filter and the fan motor in the intake side placement method as in the past, making installation and replacement work extremely easy. ing.

The clean air from which toner has been separated and removed by the filter 24 is passed through the filter hole 36. Casing hole 37. It is discharged to the outside of the device through the side frame hole 38. At this time, since there is a gap between the filter 24 and the casing 23, a part of the discharged air enters the casing 23 as shown by the arrow 40 and flows out from the cooling hole 39 in the ceiling. This outflowed air causes convection between the toner suction device 3 and the developing device 2, and the hot air is discharged to the outside. In other words, the developing device generates heat by stirring the developer, but if the temperature inside the device exceeds about 45°C, the toner will melt and the image quality will deteriorate.
To prevent this, hot air from the lower part of the developing device is removed to cool it down. In order to increase the amount of air flowing out from the cooling hole 39, the casing hole 37 can be made smaller.
The size of these holes will be determined by experiment.

(Effects) As is clear from the above explanation, according to the present invention, it is small and efficiently prevents toner scattering, the toner filter is easy to replace, and the developing device can be cooled. It is something.

[Brief explanation of drawings]

1 and 2 are vertical and horizontal sectional views showing an embodiment of the present invention, respectively, and FIG. 3 is an operation timing chart of the embodiment. 1...Shizuka fl! Latent image carrier, 2...Developer, 3...
・Toner suction device, 11...Developing sleeve, 24...
・Filter, 25.26...Fan motor, 33
．． 34...Opening. 38...Cooling hole. (Trouble figure)

Claims (1)

[Scope of Claims] 1. A suction port is provided near the contact area of the developing sleeve that contacts the electrostatic latent image carrier to suck toner scattered from the developing device, and the suction port is provided in the vicinity of the contact area of the developing sleeve to separate the sucked toner. What is claimed is: 1. A toner suction device in which a filter is provided in a flow path from an opening to a discharge port, wherein the suction port is disposed near both ends of a developing sleeve. 2. A suction port is provided near the contact area of the developing sleeve that contacts the electrostatic latent image carrier to suck toner scattered from the developing device, and the suction port leads to a discharge port to separate the sucked toner. In a toner suction device with a filter provided in the flow path, suction ports are arranged near both ends of the developing sleeve,
A toner suction device characterized in that a filter is provided near a discharge port. 3. A suction port is provided near the contact area of the developing sleeve that contacts the electrostatic latent image carrier to suck toner scattered from the developing device, and the suction port leads to a discharge port to separate the sucked toner. In a toner suction device with a filter provided in the flow path, suction ports are arranged near both ends of the developing sleeve,
A toner suction device characterized in that a filter is provided near the discharge port, and at least a portion of discharged air is flowed out toward a developing device.