JPH04204869A - Developing device - Google Patents

Abstract

PURPOSE:To smoothly replenish toner from a hopper separated and fixed by means of a simple mechanism by varying the length of a path along which toner is replenished according to the lifting positions of developing units. CONSTITUTION:The toner replenishing path 7 can be extended/reduced by joining joint pipes 71 to 73 successively and toner from a guiding part 6 is carried to the side of the developing units along the path 7. When the toner is supplied to a photosensitive drum 18 from the developing unit 84, the toner replenishing path 7 is reduced. On the other hand, when the supply of the toner to the photosensitive drum 18 from the developing unit 84 is completed, the path 7 is moved to the downward of the developing unit 8 to be switched to another developing unit. According to the movement, the toner replenishing part 7 is extended. Toner T is supplied to the developing unit through the toner replenishing path 7. Since the joint pipes 71-73 are bigger successively in the size of diameter, the toner T carried along the joint pipes 71 to 73 is not stagnated at the joints of the pipes 71-73. Thus, the toner can be supplied from the hopper 2 separated and fixed by means of the simple mechanism.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to developing devices that are arranged vertically with respect to a photoreceptor and that perform toner development. The present invention relates to a developing device that replenishes toner via a toner replenishment path.

[Conventional technology]

Moving the developing devices each containing multiple colors of toner,
Development fI of a color image forming apparatus that sequentially develops each color facing a photoreceptor drum and replenishes toner to each developing device using a hopper. The device is known.

Conventionally, in such a developing device, a hopper is connected to each developing device and moves together with the developing device;
The hopper is separated and fixed, and the developer and the hopper are connected by a flexible pipe with a toner transport mechanism (conveyance spiral) inside, and the developer is moved horizontally, and the hopper is connected to the developer. There is known a device which is fixed at a proper position above the hopper, and when the replenishment ports of the hopper and the developer are aligned, the toner in the popper is silently dropped into the developer.

1'R Ming is trying to solve the problem) However, in the case where the hopper moves together with the developer, the capacity of the hopper is structurally limited, making it difficult to increase the capacity, and the inertia is large. Therefore, the load on the drive mechanism increases. Furthermore, in the case of connecting with the flexible vibrator, the flexible pipe is expensive and the connection mechanism is complicated. Furthermore, if the hopper is fixed at a proper position above the developing device, the toner supply mechanism to the developing device can be constructed relatively easily, but since the photoreceptor drum is placed above the developing device, It is necessary to separately provide a mechanism such as a roller for pumping up toner.

The present invention has been made in view of the above, and an object of the present invention is to provide a developing device that replenishes toner from a hopper that is separated and fixed using a simple mechanism.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a developing device which is disposed in the vertical direction and extends over a photoreceptor and is integrated with the photoreceptor, a popper which is fixed in parallel at a predetermined position, and a developing device corresponding to each. The toner replenishment path includes a toner replenishment path in which the hopper and the hopper are vertically connected by a plurality of connecting pipes, and a toner conveyance means for conveying the toner in the hopper to the toner replenishment path.

Further, in a second aspect of the present invention, each toner supply path is formed of a joint pipe having the same shape as each adjacent toner supply path.

Broadly speaking, in a third aspect of the present invention, the toner replenishment path is formed of a connecting pipe having a different size from that of an adjacent toner replenishment path.

Further, in a fourth aspect of the present invention, the diameter of the joint pipe increases as it reaches the lower stage.

[Effect]

According to the developing device configured as described above, the joint pipe expands and contracts as the developing device moves up and down. Then, the toner in the hopper is supplied to the developing device through the connecting pipe by the toner conveying means.

Further, according to claim 2, since a pipe having the same shape as the adjacent toner supply path is used as the joint pipe of the toner supply path, it is more versatile. Since a pipe having a shape different from that of the adjacent toner supply path is used, it is possible to correspond to the height position of each developing device.

Further, according to the developing device of the fourth aspect, toner is prevented from accumulating at the joint of the connecting pipe.

[Real IlI example]

FIG. 4 is a schematic configuration diagram showing an embodiment of an image forming apparatus to which a developing device according to the present invention is applied.

A contact glass 11 on which a document is placed is arranged at the top of the main body of the image forming apparatus, and a document presser 12 is provided on the top surface of the contact glass 11 so as to be openable and closable.

An optical system is provided below the contact glass 11 and is configured to reciprocate in the direction of the arrow in parallel with the contact glass 11 and scan the placed original during this forward movement.

The optical system is composed of a halogen lamp 13, a reflector 14, a SELFOC lens 15 that focuses the reflected light from the document surface, a CCD 16 that receives the light from the front, and a side drive (not shown) that moves the optical system back and forth. has been done. Incidentally, although not shown in the drawings, filters are provided in front of the sensor array constituting the CCD 16 to take in received light for each color of RGB.

This optical system is driven to start scanning from the home position (indicated by the solid line) shown in the figure, scan to a predetermined position (indicated by the chain line), and then return to the home position again. is being done.

Note that the signals of the original image captured for each RGB color by this scanning are guided to a signal processing means (not shown), and level-converted there into four colors: cyan, magenta, yellow, and black. There is. The processed color signals are sequentially output from the laser emitting means 17 for each color as a laser light whose luminous intensity is adjusted, and guided to a photoreceptor drum 18, which will be described later.

A photoreceptor drum 18 is disposed inside the main body of the image forming apparatus, and around the photoreceptor drum 18 there is a charged
it;1W19. A developing device 1, a transfer device 20, a separating device 21, and a cleaning device 22 are provided.

A paper supply mechanism is provided below the main body of the image forming apparatus. The paper supply mechanism includes abrasive cassettes 23 and 24 of different sizes, a manual tray 25, pairs of transport rollers 26 to 29, and a pair of registration rollers 30, and the paper transported from the pair of registration rollers 30 is transferred to a transfer drum. 31.

The transfer drum 31 is disposed close to the photosensitive drum 18 and is controlled to rotate synchronously.

The transfer drum 31 rotates the conveyed paper integrally during the four rotations of the transfer drum 31.

That is, for each of these four rotations, the transfer process for each color is performed four times.

When the four transfer processes are completed, the paper is separated by a separating device 21 and guided to the conveyor belt 32 side.

As a discharge mechanism, a fixed one is provided on the downstream side of the conveyor belt 32.
1A133, a pair of discharge rollers 34, and a paper discharge tray 35 are provided.

Next, a configuration showing an example of the developing device f1 will be described with reference to FIG. 1.

The developing device 1 includes a developing device 11i8 in which four developing devices 81 to 84 are arranged side by side in the vertical direction, and a hopper 2, a stirring paddle 3, and a conveying spiral 4 corresponding to each developing device 81 to 84.
, a drive motor 5, a guide section 6, a toner supply path 7, and the like. As shown in FIG. 3, the openings of the toner receivers of the developing units 81 to 84 are sequentially provided at different positions, and the hoppers 2 are sequentially arranged in each of these toner receivers so as to correspond to the openings. There is.

The developing units 81 to 84 are arranged in the order of cyan, magenta, black, and yellow from above, for example.
These developing units 81 to 84 are integrally raised and lowered by an unillustrated lifting means, and are sequentially moved to a position facing the photosensitive drum 18 during reprint copying, and the toner T of each color is moved onto the photosensitive drum 18. is being supplied to.

Further, each of the developing units 81 to 84 and the laser emitting means 17 are synchronized, so that the developing units are driven up and down so that toner particles are supplied according to the laser light of each color. ing.

The hoppers 2 are fixed in parallel at predetermined positions and store toner T. The stirring paddle 3 scrapes out the toner T in the hopper 2 toward the conveyance spiral 4 side. The conveyance spiral 4 is rotationally driven by a drive motor 5 to convey the toner T upward. The guide portion 6 guides the toner T from the conveyance spiral 4 to a toner supply path 7, which will be described later, by sliding it down along an inclined surface 61.

The toner supply path 7 includes, for example, three (three stages) joint bypasses 77.
It is made expandable and contractable by sequentially connecting 1 to 73,
The toner from the guide section 6 is guided to the developing device side. That is, the joint vibrator 71 (first stage) has a funnel-shaped upper end, the upper end of which is connected to the outlet of the guide section 6, and the lower end connected to the joint vibrator 72 (second stage).

The upper end of the vibrator 73 (third stage) is connected to the vibrator 72, and the lower end is connected to the guide vibe 9 to the developing unit. Further, the inner diameter of the auger vibrator 72 is formed to be equal to or larger than the outer diameter of the joint vibrator 71, and the inner diameter of the joint vibrator 73 is formed to be equal to or larger than the outer diameter of the joint vibrator 72. Then, when the toner supply path 7 is shortened,
As shown in FIG.
Inside, a joint vibrator 72 is inserted into a joint vibrator 73. Note that the joint vibrations 71 to 73 are the joint vibrations 71 to 73 of the adjacent toner supply path 7, respectively.
It is formed to have the same shape.

Further, the lower end of the connecting vibe 71 is provided to protrude outward so as to come into contact with the inner diameter surface of the connecting vibe 72, and the lower end of the connecting vibe 72 is provided to protrude inward so as to come into contact with the outer diameter surface of the joining vibe 71. . Furthermore, the lower end of the joint vibrator 72 is provided to protrude outward so as to come into contact with the inner diameter surface of the joint vibrator 73. As shown in FIG. 2, when the developing device 8 moves downward and the toner supply path 7 is extended, the connecting pipe 71
~73 is trying not to get angry. Also, joint pipe 7
It is possible to prevent toner from scattering from each of the seams 1 to 73.

Next, the operation of the developing device 1 will be described with reference to FIGS. 1 and 2, taking the hopper 2 for replenishing toner to the developing device 84 as an example.

When the developing device 84 is supplying toner to the photosensitive drum 18, the toner supply path 7 is contracted, as shown in FIG. At this time, when the stirring paddle 3 and the conveyance spiral 4 are driven to replenish toner, the toner T in the hopper 2 is conveyed to the guide part 6 by the conveyance spiral 4, and is slid down along the slope 61 to replenish the toner. The toner toner is guided to the toner replenishment path 7, further falls within the toner replenishment path 7, and is replenished to the developing device 84.

On the other hand, when the developing device 84 finishes supplying toner to the photosensitive drum 18, the slip developing device 8 switches to another developing device.
moves downward, and the toner supply path 7 extends in response to this movement, as shown in FIG.

In this way, the toner T is supplied to the developing device through the toner supply path 7. Further, since the diameters of the connecting pipes 71 to 73 gradually increase, it is possible to prevent the toner T introduced into the toner supply path 7 from accumulating at each joint of the connecting pipes 71 to 73.

In the above description, the toner replenishment path 7 is constituted by three connecting pipes, but it may be two or four or more. Further, in the above description, the connecting pipes 71 to 73 are the connecting pipes 71 to 7 of the adjacent toner supply path 7, respectively.
3, but each developing device 81~
The dimensions of the joints 171 to 73 may be different from those of the adjacent toner supply path 7 depending on the height position of the toner supply path 84.

Alternatively, an elastic member made of sponge or the like may be attached to each joint of the joints 771 to 73 to improve the sealing performance of each of the joints 171 to 73. In this case, the connecting pipe 7
It is possible to further prevent toner from scattering from each of the seams 1 to 73.

(Effects of the Invention) As explained above, according to the present invention, the toner replenishment path length can be varied according to the agitation of the developing device, so toner is replenished to the developing device through the joint pipe, and the toner can be supplied to the developing device easily. Toner can be smoothly replenished from a hopper that is separated and fixed by a mechanism.

In addition, by making the joint pipe as a toner supply path the same shape as the joint pipe of the adjacent toner supply path, the mold etc. of the joint pipe can be shared, and the number of types is reduced, making parts management easier. Become.

Furthermore, by making the joint pipe serving as a toner supply path different in size from the joint pipe of an adjacent toner supply path, it is possible to form a suitable toner supply path according to the height position of each developing device.

Furthermore, since the diameter of the joint pipes is made to increase in order from the bottom to the bottom, it is possible to prevent toner from accumulating at each joint of the joint pipes.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing a contracted state of the toner supply path according to the present invention, FIG. 2 is a cross-sectional view of a main part showing a stretched state of the toner supply path according to the present invention, and FIG. FIG. 4 is a perspective view showing essential parts of the developing device of the present invention, and FIG. 4 is a schematic configuration diagram showing an example of an image forming apparatus to which the developing device of the present invention is applied. DESCRIPTION OF SYMBOLS 1... Developing device, 2... Hopper, 3... Stirring paddle, 4... Conveyance spiral, 5... Drive motor,
6... Guide part, 8... Developing part, 7... Toner supply path, 9... Guide vibe, 18... Photosensitive drum, 61... Inclined surface, 81-84... Developer, 71~
73...Connection pipe, T...Toner. Patent applicant Agent: Sanda Kogyo Co., Ltd.
Patent Attorney Etsushi Koai Patent Attorney Chief 1
) Masamukai Patent Attorney Takao Ire

Claims (1)

[Claims] 1. A developing device that is arranged vertically and moves up and down integrally with respect to the photoreceptor, and a hopper that is fixed in parallel at a predetermined position;
a toner supply path in which the corresponding developing devices and hoppers are vertically connected by multiple stages of connecting pipes;
A developing device comprising: toner conveying means for conveying the toner in the hopper to the toner supply path. 2. The developing device according to claim 1, wherein each of the toner replenishment paths comprises a joint pipe having the same shape as an adjacent toner replenishment path. 3. Claim 1, wherein the toner replenishment path is comprised of a joint pipe having different dimensions from the adjacent toner replenishment path.
The developing device described. 4. The developing device according to claim 1, wherein the connecting pipe has a diameter that increases toward a lower stage.