JPS6221179A - Toner supply device - Google Patents

Abstract

PURPOSE:To reduce the inclination of the reverse surface of a hopper and increase the amount of contained toner, and to prevent a cavity from being formed by providing a diaphragm which is vibrated by a conveying member for toner provided to the lower part of the hopper on the reverse slanting surface of the hopper. CONSTITUTION:The diaphragm 37 which has a raised plate 39 on the top surface is provided on the reverse slanting surface of the hopper 36 and coupled with the internal surface of the hopper 36 by a leaf spring 40, and part of the diaphragm 37 is positioned in the screw blade 38 of a screw 35. The diaphragm 37 slants in a conveyance direction during the rotation of the screw 35 and then returns to its original position with the energizing force of the leaf spring 40 when the screw blade 38 moves beyond it. Thus, the diaphragm vibrates, so a cavity is prevented from being formed in toner. Further, the inclination of the reverse slanting surface of the hopper may be small, and consequently even when the height of the hopper is decreased, the large amount of contained toner is obtained and the hopper is reduced in size.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a toner replenishing device, and particularly to a toner replenishing device that prevents so-called fogging, where only the inner toner is transported and the outer toner remains in its initial state. The present invention relates to a toner replenishing device that can prevent this.

[Background of the Invention] - Generally, in developing devices used in image forming apparatuses, etc., as the amount of toner in the two-component developer decreases,
A hopper is provided at the top of the developing device, and toner is stored inside the hopper so that toner is supplied when the amount of toner in the developer decreases.

When the toner in the hopper is supplied, it is dropped through a hole provided at the bottom of the hopper, but only the toner on the inside falls one after another, while the toner on the outside maintains its initial state. There are many cases where the hopper remains empty and becomes hollow, so-called camaraderie, and in order to prevent this hopper from forming, the lower surface of the hopper has to be made with a large slope.

However, when the lower surface of the hopper is made to have a large slope, the amount of toner that can be accommodated becomes smaller than the height of the hopper, which is contrary to the demand for downsizing of the developing device.

[Purpose of the invention]

The present invention meets the above-mentioned needs, and it is possible to reduce the slope of the lower surface of the hopper and increase the amount of toner that can be accommodated compared to the height of the hopper.
It is an object of the present invention to provide a toner replenishing device capable of preventing fogging from occurring.

[Structure of the invention]

The present invention provides a toner replenishing device that has a hopper at the top and is configured to drop the toner in the hopper and supply the toner into a developing device below, the toner replenishing device having a hopper provided at the bottom of the hopper. The hopper has a configuration in which a diaphragm vibrated by a toner conveying member is provided on the inclined lower surface of the hopper.

[Embodiments of the invention]

Embodiments of the invention shown in the drawings will be described below.

FIG. 1 shows an electrophotographic copying apparatus which is a type of image forming apparatus equipped with a toner replenishing device according to the present invention, and a charging device 2 is provided above a photosensitive drum l which is an image carrier. An exposure section 3 is located ahead of the charging device 2 in the direction of rotation of the photosensitive drum 1, and a toner replenishing device 26 is located above the charging device 2.
A developing device 4 provided with a transfer pole 5, a separation pole 6, a cleaning device 7, and a post-exposure lamp 8 are each provided close to the photoreceptor drum 1.

Between the developing device 4 and the transfer pole 5, there are provided outwardly provided two upper and lower paper feed cassettes 9A and 9B for guiding the paper therein.
an upper and lower guide plate 10a for forming upper and lower paper feed paths;
10b and a middle plate 10C, and a pair of upper and lower second paper feed rollers ll is provided between the upper and lower guide plates 10a and 10b.
a and 11b are located.

Further, paper feed rollers 12 are provided, which contact the top surface of the uppermost sheet of the sheets P in each of the paper feed cassettes 9 and feed the paper to the paper feed path.

Further, between the transfer pole 5 and the separation pole 6 and the fixing device 19, there is a conveyor belt 2 which is located downwardly as it goes forward.
A conveying device 22 is provided in which a belt 0 is stretched between rollers 21a and 21b, and a guide plate 23 is also provided so that the upper portion of the conveying belt 20 projects.

A toner collection box 24 for storing the collected toner collected by the cleaning device 7 is provided below the conveyance device 22, and this toner collection box 24 and
A communication member 25 is provided between the cleaning device 7 and the toner collected by the cleaning device 7 via the communication member 25 to the toner collection box 2.
It is designed to be guided within 4.

Further, FIG. 2 shows the developing device 4 and a toner replenishing device 26 provided above the developing device 4.
has a casing 27 that is open on the side of the photosensitive drum 1, and a stirring member 28 and a developing roller 29 are provided in the casing 27. Regulating member 30 that regulates thickness
A guide plate 31 is provided which is inclined inwardly from the regulating member 30, and near the lower end of this guide plate 31 is a conveyor pipe 3 in which an inlet port 32 is located.
3 is provided, and a screw 34 is located inside this conveying pipe 33.

Note that the inclination state of the guide plate 31 can be changed depending on the fluidity of the developer, that is, the toner concentration.

In addition, the upper part of the casing 27 has a screw 3 at the lower part.
5 is located, and a hole communicating with the hole provided in the conveying pipe 33 is provided on the lower surface of the hopper 36 on the forward side of the screw 35 in the conveying direction.

As shown in FIGS. 3 to 5, inside the hopper 36, a vibration plate 37 is provided on its inclined lower surface, and a portion 37a of the vibration plate 37 is connected to the screw blade l13 of the screw 35.
A plurality of L-shaped upright plates 39 (three in the drawing) are provided on the upper surface, and a spring plate 40 is provided between an example of the diaphragm 37 and the inner surface of the hopper 36. are connected.

On the other hand, the relationship between the conveyance pipe 33 and the toner replenishing device 26 is shown in FIG. A continuous opening 41 is provided which is successively wider in two stages.

A screw 34 is disposed inside the conveying pipe 33, and the forward side in the conveying direction is the wider direction of the opening 41 (FIG. 6).

Next, the operation of the above will be explained.

First, the photosensitive drum l charged by the charging device 2 is exposed to light to form an electrostatic latent image, and this electrostatic latent image is developed by the developing device 4 to become a toner image.

The uppermost sheet of the sheets P stored in either one of the sheet feed cassettes 9 is sent out by the feed roller 12 and is fed into the feeder formed by the upper guide plate 10a and the middle inner board 10c. Paper path or middle interior board 10C and lower guide plate 10
A second paper feed roller ll is passed through a paper feed path formed by
a.

The toner image formed on the photoreceptor drum 1 is transferred to the paper by the transfer pole 5, and then the toner image formed on the photoreceptor drum 1 is transferred to the paper by the transfer pole 5. After being conveyed by the conveying belt 20 of the conveying device 22, which is separated by 6 and whose front end is inclined downward, the paper is fixed by the fixing device 19 by a guide member that directs the leading edge of the sheet upward. The paper is ejected outward by a paper ejection roller.

Further, after the toner image has been transferred to the paper, the photosensitive drum l rotates further and reaches the cleaning device 7, and then
The residual toner on the surface is removed by the blade 7a of the cleaning device 7, and after that, post-exposure is performed using a post-exposure lamp 8, thus completing one process and waiting for the next process.

The residual toner removed by the blade 7a of the cleaning device 7 is transferred to the toner collection box 24 disposed below the conveyance device 22 via a communication member 25 that communicates the cleaning device 7 and the toner collection box 24. It falls inside and is stored inside.

On the other hand, as the above-mentioned operations are repeated, the developer in the developing device 4, that is, the toner of the two-component developer, toner and carrier, decreases, so it is stored in the hopper 36. The toners are transported to the hole by the screw 35 in order from the bottom toner and fall into the transport pipe 33 located inside the casing 27.

The toner that has fallen into the conveying pipe 33 is deposited on the front side of the regulating member 30, is conveyed by the guide plate 31, and flows down into the conveying pipe 33 from the inlet port 32. It will be mixed with the developer.

In this way, the developer whose toner content has been reduced and the toner in the hopper 36 are mixed in the conveyance pipe 33 and conveyed forward by the screw 34, but the mixture in the conveyance pipe 33, that is, the developer is screw 3
It is conveyed at a certain angle by the rotation of step 4 (
(See Fig. 7 θ1, θ2).

In this case, the state of the developer in the conveying pipe 33 is determined by the direction of rotation of the screw 34 as shown in FIG.
It becomes like bl.

That is, when the direction of rotation of the screw 34 is counterclockwise, the rotation direction is as shown in FIG. 7 (al), and when it is clockwise, it is as shown in FIG. 7 (bl).
Depending on the rotation direction of No. 4, the front side in the rotation direction is high<(h) and the rear side in the rotation direction is low with respect to the horizontal direction.

Since the developer is uniformly replenished while being transported in this state, that is, it is dropped into the casing 27 from the opening 41, the filling rate of the developer in the transport pipe 33 changes every moment in the longitudinal direction of the transport pipe 33. Along with this, the height h of the developer at the front in the rotational direction with respect to the horizontal line also changes.

FIG. 8 shows the relationship between the filling rate and the height when the screw 34 is rotated clockwise and counterclockwise. In this figure, ○ indicates a toner concentration of 5%, and . 5%, Δ means the toner concentration is 10%, O1Δ means the direction of rotation of the screw 34 is counterclockwise, and * means the direction of rotation of the screw 34 clockwise.

As is clear from this figure, the difference in height due to the filling rate is smaller in the counterclockwise direction, so when downsizing the developing device, the conveyor pipe and screw should be made smaller, and the filling rate should be increased. Therefore, replenishing by rotating the screw counterclockwise is more advantageous for uniform replenishment.

Note that since the developer is dropped from the opening 41 of the conveying pipe 33 by rotating the screw 34 clockwise or counterclockwise, the height of the lower edge of the opening 41 of the conveying pipe 33 is as shown in FIG. It is preferable to correspond to a curve, and in the illustrated embodiment, the lower edge of the opening becomes downward as it goes forward, and the tip has a two-step sloped lower edge that descends with a large slope.

In this way, the developer is uniformly dropped onto the downward part of the casing 27 of the developing device 4, and the developer is sequentially dropped into the hopper 36.
The toner inside falls into the conveying pipe 33, but due to the low fluidity of the toner, only the toner inside is conveyed on the slanted lower surface of the hopper, and the toner outside retains its shape. However, in the present invention, a diaphragm 37 having an upright plate 39 on the upper surface is located on the inclined lower surface, and this diaphragm 37 is of the Hong type 36.
Since the diaphragm 37 is connected to the inner surface by the spring plate 40 and a part of the diaphragm 37 is located within the screw blade 38 of the screw 35, the diaphragm 37 tilts in the conveyance direction when the screw 35 rotates. When the screw blade 38 climbs over the screw blade 38, it returns to its original state due to the biasing force of the spring plate 40, and thus it is possible to prevent the toner from becoming blurred due to vibration.

Therefore, the slope of the lower surface of the hopper may be small, and even if the height of the hopper is lowered, the hopper can be made smaller and accommodate a larger amount of toner.

〔Effect of the invention〕

By having the above-mentioned structure, the present invention can prevent the toner from forming a so-called blur inside the hopper, and reduce the slope of the lower surface required to cause the toner to fall. Therefore, the storage capacity of the hopper can be increased, and the height of the hopper can also be lowered.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an image forming apparatus equipped with an image forming apparatus according to the present invention, FIG. 2 is a schematic diagram showing a developing device and a toner replenishing device provided above it, and FIG. 3 is a diagram showing a diaphragm. , FIG. 4 is a schematic diagram of the toner replenishing device, and FIG. 5 is a schematic perspective view showing the relationship between the toner replenishing device and the conveying pipe.
Figure 6 is a diagram showing the relationship between the conveyance pipe and the screw, Figure 7 (al (b) is a diagram showing the relationship between the rotational direction of the screw and the height of the toner, and Figure 8 is a diagram showing the relationship between the height of the toner and the filling rate. 1...Photosensitive drum 2...Charging device 4...Developing device 5...Transfer pole 6... ... Separation electrode 7 ... Cleaning devices 9A, 9B ... Paper feed cassette 22 ... Transport device 26 ... Toner supply device 31 ...・Guide plate 32... Inflow port 33... Conveying pipe 34.35... Screw 36... Honopa 37... Vibration plate 38 ...Screer blade 39...Upright plate 40...Spring plate 41...Opening part Fig. 3

Claims (2)

[Claims] (1) A toner replenishing device that has a hopper at the top and is configured to drop the toner in the hopper and supply the toner into the developing device below, and the toner supply device is provided at the bottom of the hopper. A toner replenishing device characterized in that a diaphragm vibrated by a conveying member is provided on an inclined lower surface of the hopper. (2) The toner replenishing device according to claim 1, wherein the diaphragm is placed on the inclined lower surface of the hopper and is connected to the inner surface of the hopper by a spring plate.