JPH09160366A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively evade the leakage of toner accompanying replenishment thereof, the soiling inside a machine, the deterioration of image quality or the like by fitting one end of a pipe consisting of a elastic material to either one of both members so as to be located between the toner discharge part and the toner replenishment port. SOLUTION: In the vicinity of the toner discharge port 710 of a hopper 707, a lib 711 is formed. In the vicinity of the toner replenishment port 704 of a developing unit 701 the lib 705 is formed. On the lib 711 of the hopper 707 side, a pipe 712 consisting of an elastic member such as a bellows-worked thin silicone rubber is fixed, and an annular magnet 713 is fitted to a free end of the pipe. Moreover, the annular magnet 706 is fitted on the lib 705 on the developing unit 701 side. When the toner discharging port 710 and the toner replenishment port 704 reach a position opposing each other, magnets 713 and 706 is made adjacently opposing each other, attracted by each other by a magnetic force, and a gap between the both ports is clogged by the elastic pipe 712.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrostatic copying machine and a printer.

[0002]

2. Description of the Related Art In the image forming apparatus as described above, when the toner accommodated in the developing device is insufficient, the toner is usually replenished from a separately provided hopper. . By the way, in a device such as a color image forming apparatus, which is provided with a plurality of developing devices and is capable of moving each developing device between a standby position and an operating position in order to selectively contribute to the development. , A gap is created between the toner discharge port of the hopper fixed to the main body of the apparatus and the toner supply port of the moving developing device, and the toner is supplied through this space (usually free fall). The toner may leak due to the air flow in the main body of the apparatus, resulting in contamination of the inside of the apparatus and deterioration of image quality due to the contamination.

A mode of toner replenishment in such an image forming apparatus will be briefly described below with reference to FIGS. 10 to 12. FIG. 10 is a side cross-sectional view of a main part of a color image forming apparatus including four developing devices, in which an image of a document 0 placed on the top of the apparatus is a well-known optical system, laser scanner, or the like. The exposure apparatus having the above-mentioned means forms an electrostatic latent image by projecting it onto the surface of the rotating cylindrical image carrier 1 uniformly charged by the primary charger 2.

When the latent image reaches a developing portion where the developing device 4 is arranged oppositely, toner is applied to the latent image to form a toner image. Since the illustrated apparatus uses toners of four colors of yellow, magenta, cyan, and black, the developing device 4 includes the yellow developing device 4Y, the magenta developing device 4M, and the cyan developing device 4 which contain the toners of the respective colors.
Four developing devices C and a black developing device 4BK are provided, and these can selectively take an operating position near the image carrier 1 and a retracted position separated from the operating position.

The formation of a color image will be briefly described. When a latent image corresponding to the yellow component color of the original is formed on the image carrier 1 and reaches the developing portion where the developing device 4 is arranged, yellow development is performed. The container 4Y takes an operating position near the image carrier 1 and applies yellow toner to the latent image to form a yellow toner image.

When the toner image reaches the transfer portion where the image carrier 1 and the transfer drum 6 rotating in synchronization with the image carrier 1 face each other, by this time, the transfer material (not shown) has the suction roller 2
0, supplied to the transfer drum 6 via the adsorption charger 19 and adsorbed, and then reaches the transfer site. Here, the yellow toner image on the image carrier side is transferred to the transfer material by the action of the transfer charger 7.

After that, the transfer material rotates while remaining on the transfer drum 6. On the other hand, after the residual toner remaining on the image carrier even after the transfer is removed by the cleaner 5, a latent image of the magenta component color of the original is formed on the image carrier in the same manner as described above, and this is the developing device 4. When it reaches the position opposite to, the magenta developing unit 4M reaches the operating position by this time, and the magenta toner is applied to the latent image to form the magenta toner image.

Further, when the magenta toner image reaches the transfer portion, the yellow toner image on the transfer drum arrives at the transfer portion at the same timing, and the magenta toner image is superposed and transferred. In the same manner, the cyan toner image and the black toner image are sequentially transferred to the transfer material, and the transfer process ends.

After that, the transfer material is separated from the transfer drum 6 by the action of the separation claw 14, passes through the conveying path 17, and is fixed in the fixing device 18.
It is assumed that the toner image is fixedly fixed on the transfer material and discharged to the outside of the machine. The transfer drum 6 is an electrostatic charger 10, 1
The toners that have been subjected to static elimination by 1, 29 are removed by the cleaner 15 and are ready for the next transfer step.

In such a device, the image carrier 1 and the developing device 4 are provided in the device in order to replenish toner to each developing device.
A hopper is disposed substantially at the front position. "Figure 11"
Shows a side sectional view of this hopper, which will be described below.

Reference numeral 200 denotes a hopper unit, 202
Is a frame, which is equipped with hoppers 201Y, 201M, 201C, and 201BK that respectively store yellow toner, magenta toner, cyan toner, and black toner. Inside each hopper, stirring members 301Y, 301M, 3
01C and 301BK, and conveying members 300Y, 300M and 30 each having a conveying screw built in at the lower end of the hopper.
0C and 300BK are provided.

Toner discharge ports 203Y, 203M, 203C and 203BK formed at the ends of the respective transport members are provided with toner supply ports 400Y, 400M and 400C of the developing units 4Y, 4M, 4C and 4BK on the apparatus main body side. The toner is replenished while facing 400 BK. The figure shows the developing unit in the inoperative position, and there are some gaps between each toner discharge port and toner replenishment port, but when the developing unit moves to the operating position, this gap becomes almost zero. And

FIG. 3 is a plan view showing the hopper unit 200 as seen from above the apparatus main body. Reference numeral 6
29 is a front frame of the main body of the apparatus, and a stay 6 provided on the front frame.
29a and 629b, the hopper unit 200 slides in a direction indicated by an arrow A by a slide rail 628 fixed to a member 627, one of which is fixed to a stay 629b and the other to a hopper frame, and a slider 622a which slides on the stay 629a. It is mounted so that it can move freely.

As described above, when replenishing toner to the developing device, the hopper unit 200 is moved in the direction of arrow A, and the toner discharge ports 203Y to 203BK of each hopper are developed as shown in FIG. Supply side 400
The toner is supplied so as to face Y to 400BK.

In the toner replenishing means having such a structure, as described above, a gap is formed between the toner discharge port of the hopper and the toner replenishment port of the developing device when the replenishment is repeated. Since it is unavoidable, it is difficult to prevent the toner from leaking into the device, the contamination of each part in the device due to this, and the deterioration of the image quality.

The present invention has been made to cope with such a situation, and in the above-mentioned image forming apparatus, a flexible vip-shaped member is provided between the toner discharge port of the hopper and the toner supply port of the developing device. To enable free movement of the two and to reliably prevent the formation of a gap between the two to prevent leakage of toner during toner replenishment, resulting in contamination inside the machine, deterioration of image quality, etc. It is an object of the present invention to provide an image forming apparatus that can be avoided.

[0017]

Configuration of the Invention

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a developing device having a toner replenishing port, and a hopper having a toner discharge port for accommodating toner to be replenished to the developing device. And an image formation for replenishing toner in the hopper by dropping the toner in the hopper to replenish the toner by reciprocally moving the developing device and the hopper to superimpose and align the toner replenishing port position and the toner ejecting port position. In the apparatus, one end of a pipe made of an elastic material is attached to one of the both members so as to be located between the toner discharge port and the toner supply port, and the other end of the pipe and the pipe are attached. An image forming apparatus (1), characterized in that a connecting member for contacting and separating the toner discharge port or the toner replenishment port on the non-wearing side is provided. , Pa The image forming apparatus (2) is characterized in that the coupling strength and length are set so that the coupling member abuts when the hopper is superposed on the developing device and is disengaged when the hopper is separated from the developing device, or The image forming apparatus (3) according to the above (1) or (2), wherein the coupling member is a magnet.
Alternatively, in any one of the above (1) to (3), the image forming apparatus (4) is characterized in that the pipe is any one of rubber, cloth, a coil spring, or a combination of two or more thereof. ), Or (1) to (3) above
The image forming apparatus (5) according to any one of (1) to (5) above, characterized in that the pipe is composed of an annular magnetic member and powder adhered to the annular magnetic member by magnetic force, or An image forming apparatus (6), wherein the annular magnetic member is a coil spring made of a magnetic material, or
In the above (5), the image forming apparatus (7), wherein the annular magnetic member is a plurality of ring-shaped magnets connected in the central axis direction, or a developing device having a toner supply port, A hopper for storing toner to be replenished to the developing device with a toner ejection port, and when replenishing the toner, the developing device and the hopper are relatively moved to move the toner replenishment port position and the toner ejection port position. An image forming apparatus in which toner in a hopper is dropped and replenished to a developing device by superimposing alignment, and magnets are respectively provided at the toner ejection port and the toner replenishment port.

With such a configuration, in the image forming apparatus in which the hopper and the developing device are relatively moved at the time of replenishing the toner, it is possible to effectively prevent the toner from leaking from the replenishing portion at the time of replenishing the toner.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS "FIG. 1" is a side sectional view and a side view showing an embodiment of the present invention, in which only the toner discharge port on the hopper side and the toner supply port on the developing unit side are shown. ing.
1A shows a toner discharge port portion on the hopper side, and a reference numeral 707 indicates a toner in the hopper, which is conveyed to a discharge unit 708 by a conveying screw 709 disposed inside the hopper, and then discharged from the discharge port 710. Shall be done.
A rib 711 is formed around the toner discharge port 710.

FIG. 2B shows a toner replenishing port portion of the developing device mounted on the main body of the image forming apparatus. The developing container 702 of the developing device 701 is provided with a replenishing port 704 for receiving the toner from the hopper. The toner received from the replenishing port is uniformly distributed in the longitudinal direction of the developing device by the conveying screw 703. A rib 705 is formed around the toner supply port 7-4.

Further, as shown in FIG. 1A, a pipe 712 made of an elastic material such as bellows-processed thin silicon rubber is fixed to the rib 711 on the hopper 707 side. An annular magnet 713 is attached to the free end. Further, as shown in FIG. 3B, an annular magnet 706 is attached to the rib 705 on the developing device 701 side. And these magnets 71
The polarities of Nos. 3 and 706 are set so that the opposite surfaces are attracted to each other.

FIG. 1C shows that the hopper 707 has moved to a position where the toner discharge port 710 and the toner supplementary supply port 704 of the developing device 701 are opposed to each other.

The toner discharge port 710 and the toner supply port 7
When it comes to a position facing 04, the magnet 7
13 and 706 face each other in close proximity, and both are attracted by the magnetic force, and the gap between both ports is closed by the elastic pipe 712. Although the developing device moves in the direction of arrow 714 so as to come close to the image bearing member during operation, it can be easily understood that this load can be sufficiently absorbed by allowing the elasticity of the pipe 712 to have an appropriate margin. .

When the hopper is separated from the developing unit, if the hopper is moved toward the standby position, the pipe 712 is first stretched, and then both magnets 706 and 713 are peeled off to the position shown in FIG. 1 (a). Return to. Since both magnets attract each other at a position where the magnetic force acts most strongly, that is, at a position where the centers of the two magnets substantially coincide with each other, no special positioning means is required.

FIG. 2 is a front view showing the relationship between the hopper side toner discharge port and the developing device side toner supply port when the image forming apparatus main body is viewed from the front. In this apparatus, the retracted position (dotted line position in the drawing) of the developing device and the operating position (solid line position in the drawing) are shown to be displaced in the left-right direction.

In such an apparatus, it is necessary to set the toner discharge port on the hopper side so as to come directly above the position of the developing device during operation so that the toner drops vertically. Whether or not the magnet is attracted at the release position depends on the bellows state of the pipe, the position of both magnets, the magnetic force, etc. However, once the developing device is brought to the operating position, both are correctly attracted at the position.

FIG. 3 is a side view of the essential parts of the second embodiment. The structures of the magnets, pipes, etc. arranged between the hopper side toner discharge port and the developing device side toner supply port are basically the same as those shown in FIG. In this device, between the lower part of the hopper and the magnet on the same side,
They are connected by wires such as reference numerals 715 and 716 and a strong string.

The length of the wire or the like is set so that the wire is in a substantially tensioned state or a state close to this when the hopper side magnet and the developing device side magnet are in contact with each other. With this configuration, when the two magnets are separated, they can be separated without burdening the pipe, so that the life of the pipe can be extended.

FIG. 4 is a side view of the essential parts showing the third embodiment. This figure shows only the configuration on the hopper side, and the configuration of the elastic pipe and the configuration of the developing device side (not shown) are the same as those shown in FIG. 1 above.

In the illustrated apparatus, a coil spring 717 is loosely wound between the lower surface on the hopper side and the annular magnet. With this configuration, the pipe arranged between the hopper-side toner discharge port and the developing-unit-side toner replenishment port has only the sealing function between them, and the joining and releasing of both ports is done exclusively by the coil. It is possible to rely on springs. It will be readily understood that the device shown in FIG. 3 can be used together with this device. [FIG. 5] A modified example of the above apparatus, in which the structure of the pipe portion is strong, the structure in which the pipe and the annular magnet are arranged at the tip thereof and the coil spring portion are attached to the toner supply port on the developing device side. It is also possible.

FIG. 6 is a side view of the essential parts showing the fourth embodiment. In the illustrated apparatus, the lower surface of the hopper and the annular magnet are connected by a magnetized coil spring 718, and this is sprinkled with magnetic powder such as a carrier used for a developer. With such a structure, a magnetic seal is formed, so that it is possible to prevent the magnetic seal from leaking to the outside when replenishing the toner.

"FIG. 7" is a side view of the essential portions of the fifth embodiment. In this device, a plurality of annular magnets 7
20 is connected and formed in a tubular shape by flexible wires 721 and 722, and magnetic powder is held between the magnets by a magnetic force to form a magnetic seal. Even with such a configuration, the same effect as that of the apparatus of the above embodiment can be obtained.

FIG. 8 is a partially cutaway side view showing the sixth embodiment. In this apparatus, rectangular magnets 724 and 725 are attached to the tip of the pipe attached to the hopper side through a plate member 726, and a similar magnet 728 is also attached to the replenishing port on the developing device side. , 727 are provided. With such a configuration, the self-centering action does not work between the magnet on the hopper side and the magnet on the developing device side, but the configuration is simple and contributes to cost reduction.

FIG. 8 is a side view showing the seventh embodiment. In this device, the toner discharge container 7 on the hopper side
An annular magnet 732 is directly attached to 31, and a magnet 733 is provided at the toner supply port on the developing device side. Magnet 73 on the hopper side when toner is supplied as shown
2 is located immediately above the magnet 733 on the developing unit side, and at this time, a magnetic seal is formed by the magnetic line of force between both magnets, so that toner leakage can be prevented. This apparatus is effective when using a one-component magnetic toner containing magnetite.

The embodiments of the present invention have been described above.
It goes without saying that the devices of these embodiments can be used individually to obtain the desired effects, but it goes without saying that the use of a combination of a plurality of embodiments is not hindered.

[0036]

As described above, according to the present invention,
Equipped with a developing device and a hopper that replenishes toner to this, when replenishing toner, the toner ejection port on the hopper side is moved so that it is vertically overlapped with the toner replenishing port on the developing device side to replenish toner from the hopper In the image forming apparatus configured so as to sufficiently seal between the toner discharge port and the toner replenishment port, it is possible to effectively prevent the toner from leaking through the gap between these ports, It has a remarkable effect of preventing the contamination of each part in the apparatus and the deterioration of the image quality due to the contamination.

[Brief description of the drawings]

FIG. 1 is a sectional view and a side view of a main part showing a first embodiment of the present invention.

FIG. 2 is a side view of essential parts showing a case in which the above-described device is applied to an image forming apparatus having another configuration.

FIG. 3 is a side view of an essential part showing a second embodiment of the present invention.

FIG. 4 is a side view of an essential part showing a third embodiment of the present invention.

FIG. 5 is a side view of an essential part showing a modification of the above.

FIG. 6 is a side view of an essential part showing a fourth embodiment of the present invention.

FIG. 7 is a side view of an essential part showing a fifth embodiment of the present invention.

FIG. 8 is a partially cutaway side view of a main part showing a sixth embodiment of the present invention.

FIG. 9 is a side view of an essential part showing a seventh embodiment of the present invention.

FIG. 10 is a schematic side sectional view of an image forming apparatus suitable for applying the present invention.

FIG. 11 is a front view of a hopper unit mounted on the same.

FIG. 12 Same as above

[Explanation of symbols]

0 original document 1 image carrier 2 primary charger 3 exposure device 4 developing device 4Y, 4M, 4C, 4BK developing device 5 cleaner 6 transfer drum 7 transfer charger 10, 11, 29 static eliminator 15 cleaner 17 transport path 18 fixing device 19 Adsorption Charger 20 Adsorption Roller 200 Hopper Unit 201Y, 201M, 201C, 201BK Hopper 203Y, 203M, 203C, 203BK Toner Discharge Port 400Y, 400M, 400C, 400BK Toner Supply Port 701 Developer 707 Hopper 706, 713 Magnet 712 Elastic Pipe 715, 716 Wires 717, 718 Coil springs 720 Magnets 724, 725, 727, 728 Magnets 728 Plate members 732, 733 Magnets

Claims (8)

[Claims] 1. A developing device having a toner replenishing port, and a hopper having a toner discharge port for accommodating toner to be replenished to the developing device. When the toner is replenished, the developing device and the hopper are relatively moved. In the image forming apparatus in which the toner replenishment port position and the toner ejection port position are superposed and aligned to drop and replenish the toner in the hopper to the developing device, the image forming device is located between the toner ejection port and the toner replenishment port. As described above, one end of a pipe made of an elastic material is attached to one of the both members, and the other end of the pipe and the toner discharge port or toner replenishment port on the side where the pipe is not attached,
An image forming apparatus comprising a connecting member for contacting and separating the two. 2. The connecting strength and length of the pipe are set so that the connecting member abuts when the hopper is superposed on the developing device and detaches when the hopper is separated from the developing device. The image forming apparatus described in 1). 3. The image forming apparatus according to claim 1, wherein the coupling member is a magnet. 4. The pipe according to claim 1, wherein the pipe is made of rubber, cloth, a coil spring, or a combination of two or more thereof. Image forming apparatus. 5. The image forming apparatus according to claim 1, wherein the pipe is composed of an annular magnetic member and powder adhered to the annular magnetic member by magnetic force. 6. The image forming apparatus according to claim 5, wherein the annular magnetic member is a coil spring made of a magnetic material. 7. The image forming apparatus according to claim 5, wherein the annular magnetic member is a plurality of ring-shaped magnets connected in the central axis direction. 8. A developing device having a toner replenishing port, and a hopper having a toner discharge port for accommodating toner to be replenished to the developing device, wherein the developing device and the hopper are relatively moved when replenishing the toner. In the image forming apparatus in which the toner replenishment port position and the toner ejection port position are superposed and aligned to drop and replenish the toner in the hopper to the developing device, magnets are respectively provided at the toner ejection port and the toner replenishment port. An image forming apparatus characterized by the following.