JPH0246481A - Developing device - Google Patents

Abstract

PURPOSE:To prevent toner from scattering off from the space of a toner hopper cover by providing guide members leading air leaking through a toner replenishing route from a developing device main body away from the side of the toner hopper cover. CONSTITUTION:When development is not carried out, the rotating cylinder 12b of a developing magnet roller 12 and the rotating cylinder 14b of a carrying magnet roller 14 are rotated to carry and accumulate a developer 8 in the space A of a shutter mechanism 11. The carrying and accumulation of the developer 8 compress the air in the space A' and leaks into the toner hopper 2 from the toner replenishing route 15. The leaking air is led crosswise and downward by the 1st guide member 16 so as to be away from the cover 5, and the 2nd guide member 17 further leads the air away from the cover 5. Thus, toner is prevented from scattering toward the cover 5 of the toner hopper 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing device that supplies developer onto a photoreceptor, and is used in, for example, electrostatic transfer copying machines and laser printers.

[Conventional technology]

In a general developing device, as shown in FIG. 2, a shutter mechanism 24 is provided inside the main body 21.
This shutter mechanism 24 switches between supplying the developer 22 contained in the developing device main body 21 to the developing magnet roller 23 and stopping the supply. Also, a toner hopper 2 disposed on the developing device main body 21
A toner replenishing roller 30 is disposed within the toner replenishing roller 8, and a space below the toner replenishing roller 30 and a space above the shutter mechanism 24 communicate with each other to form a toner replenishing path 31.

During development, the shutter mechanism 24 is in an open state, and the developer 22 supplied through the shutter mechanism 24 forms a magnetic brush on the circumferential surface of the rotating cylinder 23a of the developing magnet roller 23, so that only the toner is removed. The photoreceptor is sequentially supplied onto the photoreceptor heald 25. On the other hand, during non-development, the shutter mechanism 24 is in a closed state, and the supply of the developer 22 to the developing magnet roller 23 is stopped. Then, as shown in FIG. 3, the rotating cylinder 23a of the developing magnet roller 23 and the rotating cylinder 26a of the conveying magnet roller 26 provided above the rotating cylinder 23a continue to rotate, and the developer 22 gradually moves to the shutter mechanism. It will be transferred and deposited in the space above 24.

[Problem to be solved by the invention]

However, when the air in the space is compressed by the transfer and accumulation of the developer 22, this compressed air leaks into the toner hopper 28 from the toner supply path 31, and as a result, the toner in the toner hopper 28 is The toner is blown upwards from the toner supply roller 3o (indicated by → in the figure),
A situation where particles are scattered to the outside through the gap in the lid body 28a (indicated by → in the figure) tends to occur. Furthermore, when the toner scatters to the outside and adheres to the charging charger or the optical system, there is a drawback that image quality is significantly degraded.

[Means to solve the problem]

In order to solve the second problem, the developing device according to the present invention includes a developing magnet roller for supplying the developer onto the photoreceptor, and a mechanism for supplying and stopping the developer to the developing magnet roller. The developing device main body includes a switching shutter mechanism, and a conveying magnet roller that receives the developer on the rotating cylinder of the developing magnet roller and transfers and deposits the developer in a space above the shutter mechanism. A toner replenishment roller is disposed in a toner pumper disposed on the main body, and a space above the shutter mechanism in the developing device main body communicates with a space below the toner replenishment roller in the toner pumper. In a developing device in which a toner supply path is formed, a guide member is provided near the toner supply roller to guide air leaking from the developing device main body through the toner supply path in a direction away from a lid side of the toner pumper. It is characterized by

[For production]

According to the above configuration, the air in the space above the shutter mechanism is compressed by the transfer and accumulation of the developer, and even if this compressed air leaks into the toner hopper from the toner supply path, this air will not flow into the toner hopper. Since the toner is guided away from the lid of the toner hopper, it is possible to prevent the toner from blowing up toward the lid of the toner hopper. Therefore, it is possible to prevent toner from scattering to the outside from the gap in the lid of the toner hopper, and it is possible to avoid a significant deterioration in image quality caused by such toner scattering to the outside.

〔Example〕

An embodiment of the present invention will be described below based on FIG.

In the developing device according to the present invention, as shown in FIG.
A first agitation roller 6 is rotatably provided near a toner replenishment opening 1a formed in the upper wall of the developing device main body 1. A developer supply passage 9 is formed below the first stirring roller 6 by a separator 7 and a side wall portion of the developing device main body 1, and within this developer supply passage 9, a second stirring roller 10 and a shutter mechanism 11 are formed. is installed. The shutter mechanism 11 is the second stirring roller 1
It is rotatably provided concentrically on the outer circumferential side of the developer 8, and by rotating 90 degrees, it switches between communicating and blocking the developer supply passage 9, and transfers the developer 8 to the developing magnet roller 12. It is designed to switch between supplying and stopping the supply.

The developing magnet roller 12 is composed of a magnet 12a and a rotary cylinder 12b that is rotatably provided concentrically with the magnet 12a on the outer peripheral side of the magnet 12a. 8 to form a magnetic brush, which sequentially supplies only toner onto the photoreceptor heald 13. Note that the shutter mechanism 11
A toner concentration sensor 18 and a dock 19 are provided between the developing magnet roller 12 and the toner concentration sensor 18.
At step 9, the magnetic brush is controlled to stand up.

A conveying magnet roller 14 is provided above the developing magnet roller 12 . Conveyance magnet roller 14
is composed of a magnet 14a and a rotating cylinder 14b rotatably provided concentrically with the magnet 14a on the outer circumferential side thereof, and receives the developer 8 on the rotating cylinder 12b of the developing magnet roller 12. This is then transferred and deposited in the space A above the shutter mechanism 11.

A toner hopper 2 for replenishing toner to the developing device main body 1 is disposed at the top of the developing device main body 1. Opening 1 of developing device main body 1 in toner hopper 2
An opening 2a for toner replenishment is formed in the portion facing a, and a toner replenishment path 15 is formed by communicating this opening 2a with the opening 1a. A toner stirring blade 3 and a toner replenishing roller 4 are rotatably provided inside the toner hopper 2, and a lid 5 is provided at the upper opening of the toner hopper 2.

At a predetermined position near the toner replenishing roller 4 and on the side of the toner agitating blade 3, air leaked from the developing device main body 1 through the toner replenishing path 15 is directed laterally and downwardly. A first guide member 16 having a bent portion 16a formed at the upper portion is provided to guide the guide member. moreover,
Above this first guiding member 16, this first guiding member 1
A second guiding member 17 is provided to move the air that could not be completely guided in step 6 away from the lid body 5. Of course, these first and second guide members 16 and 17 are connected to the toner stirring blades 3.
They are each attached to the inner wall of the toner hopper 2 so as not to interfere with the toner hopper 2.

In the above configuration, during development, the shutter mechanism 1
1 is in the open state, and the developer 8 supplied through the developer supply passage 9 is applied to the rotating cylinder 12 of the developing magnet roller 12.
A magnetic brush is formed on the circumferential surface of b, so that only toner is sequentially supplied onto the photoreceptor heald 13. On the other hand, during non-development, the shutter mechanism 11 is in a closed state, and the supply of the developer 8 to the developing magnet roller 12 is stopped. And this developing magnet roller 12
The rotating cylindrical body 12b and the rotating cylindrical body 14b of the conveyance magnet roller 14 continue to rotate, and the developer 8 that has been attracted and conveyed by the magnetic force of the N2 pole of the magnet 12a is attracted to the 81st pole of the magnet 14a of the conveyance magnet roller 14. is magnetically attracted to the rotating cylinder 14b and moves onto the rotating cylinder 14b.
By the rotation of b, the space A above the shutter mechanism 11 gradually increases.
It will be transferred and deposited.

Here, the air in the space A' is compressed by the transfer and accumulation of the developer 8, and this compressed air is transferred to the toner supply path 1.
Even if the air leaks into the toner hopper 2 from the toner hopper 5, this air is guided away from the lid 5 in the lateral and downward direction (indicated by → in the figure) at the first guide portion 1jA' 16.
Further, since the air that cannot be guided in the lateral direction is guided away from the lid 5 by the second guiding member 17 (indicated by → in the figure), the toner is directed toward the lid 5 side of the toner pumper 2. You can prevent it from blowing up. This prevents toner from scattering to the outside from the gap in the lid 5 of the toner hopper 2, and it is possible to avoid significant deterioration in image quality caused by toner scattering to the outside. .

〔Effect of the invention〕

As described above, the developing device according to the present invention includes a developing magnet roller for supplying the developer onto the photoreceptor, a shutter mechanism for switching between supplying and stopping the developer to the developing magnet roller, and the developing device. The developing device main body is provided with a conveying magnet roller that receives the developer on the rotating cylinder of the magnetic roller and transfers and deposits the developer in the space above the shutter mechanism, and is disposed on the developing device main body. A toner replenishment roller is disposed within the toner hopper, and a space above the shutter mechanism in the developing device main body communicates with a space below the toner replenishment roller in the toner hopper to form a toner replenishment path. In the developing device, a guiding member is provided near the toner replenishing roller to guide air leaking from the developing device main body through the toner replenishing path in a direction away from the lid of the toner hopper.

This can prevent the toner from scattering to the outside from the gap in the lid of the toner hopper, and has the effect of avoiding a significant deterioration in image quality caused by the toner scattering to the outside.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the present invention, and is a sectional view showing the internal structure of the developing device, and FIGS. 2 and 3 show conventional examples, and FIG. 2 shows the developing device. FIG. 3 is a sectional view showing the internal state of the developing device during non-development. 1 is a developing device body, 2 is a toner hopper, 6 is a first stirring roller, 7 is a separator, 8 is a developer, 9 is a developer supply passage, 10 is a second stirring roller, 11 is a shutter mechanism,
12 is a developing magnet roller, 13 is a photoreceptor heald, 1
4 is a conveyance magnet roller, 15 is a toner supply path, 16
17 is a first guiding member, and 17 is a second guiding member.

Claims (1)

[Scope of Claims] 1. A developing magnet roller for supplying developer onto the photoreceptor, a shutter mechanism for switching between supplying and stopping the developer to the developing magnet roller, and a rotating cylinder of the developing magnet roller. The developing device main body is provided with a conveyance magnet roller that receives the developer on the body and transfers and deposits it in the space above the shutter mechanism, and a toner hopper disposed on the developing device main body includes In the developing device, a toner replenishing roller is provided, and a space above the shutter mechanism in the developing device main body communicates with a space below the toner replenishing roller in the toner hopper to form a toner replenishing path. A developing device characterized in that a guide member is provided near the toner replenishing roller to guide air leaking from the developing device main body through the toner replenishing path in a direction away from the lid of the toner hopper.