JPH0651636A - Developing device - Google Patents

Abstract

PURPOSE:To provide a developing device surely releasing toner in a toner cartridge into a toner hopper and improving the stirring capacity of a toner agitator during a replenishing action and further, a developing device securing the safety of a user during the replenishing action and not scattering the toner and dropping a developer, but saving power and improving durability. CONSTITUTION:In the developing device provided with the toner cartridge 13 having a shutter 14 for dropping the toner housed inside from the opening of the bottom surface and the toner hopper 11 having the opening for attaching/ detaching the toner cartridge 13, the toner agitator 12 sending out the toner in the toner hopper 11 toward a toner replenishing part while agitating the toner, linked with an operation for replenishing the toner from the cartridge 13 is freely rotatably supported in the toner hopper 11, and simultaneously, driving means 18 and 19 rotating/driving the toner agitator 12 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry developing device in an image forming apparatus such as a copying machine, a facsimile or a printer, and more particularly to an improvement of a toner replenishing device used in the dry developing device. .

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine,
An electrostatic latent image is formed on a drum-shaped latent image carrier, and the electrostatic latent image is made visible by a powdery developer. In such a developing device, a toner replenishing device is detachably attached to the developing device main body, and toner is replenished to the developing device main body from here.
In this type of toner replenishing device, a toner agitator is provided in a container for containing toner (hereinafter referred to as a toner hopper), and by rotating this, a toner for replenishment is agitated while being agitated. Toner is being replenished from the replenishment section to the developing device body. Toner is replenished by mounting a new toner cartridge on the upper surface of the toner hopper while the toner inside the toner hopper is at the end or near end. An example of such a toner cartridge is disclosed in Japanese Patent Application Laid-Open No. 62-127876. That is, when the toner cartridge is mounted on the developing device, the rack provided on a part of the lower surface of the toner cartridge, which is the toner releasing portion, and the pinion provided on the developing device side are engaged with each other.
The rack and the pinion function by pushing and pulling the toner cartridge, and the sheet member that seals the toner opening portion is peeled or reattached.

In such a replenishing operation, there are a method of stopping all driving and a method of continuously driving the developing device. In the former method of stopping all driving, if the toner agitator in the toner hopper is stopped near the top during replenishment, the toner agitator pulls the shutter of the toner cartridge and replenishes the toner in the toner hopper with the toner agitator blocking plate. The toner replenishment operation ends before the toner in the cartridge completely moves into the toner hopper, and a high proportion of new toner remains in the toner cartridge.
Therefore, it becomes difficult to copy the number of copies guaranteed by the toner capacity of the toner cartridge. From such a point, in Japanese Patent Laid-Open No. 1-267671, when the toner end sensor detects the end of the toner in the toner hopper, the developing device is driven in a posture in which the toner agitator is vertically downward in the toner hopper. A configuration for stopping is disclosed. In this state, the toner cartridge is mounted above the toner hopper, and even if the new toner is released, the toner is not clogged and is smoothly accommodated in the toner hopper. However, during the replenishment operation, a large amount of toner spills on the toner agitator, so that the toner is deformed every time the replenishment is repeated, and the stirring ability of the toner agitator deteriorates. On the other hand, in the latter method, the developing device rotates at a high speed during the replenishing operation, and therefore, if the driving portion is exposed, it poses a danger to the user, and toner scattering from the developing roller during this period ( Or drug drop) is inevitable. Furthermore, the consumption of the driving power during this period makes the running cost of the device expensive.

[0004]

SUMMARY OF THE INVENTION In the above-described conventional developing device, in addition to the problem of deteriorating the stirring ability of the toner agitator, the danger to the user, toner scattering (or toner drop), the running cost of the device is high and the durability is high. There was a problem such as lack of. Therefore, the present invention is intended to solve such a problem. That is, an object of the present invention is to provide a developing device that surely releases (moves) the toner in the toner cartridge into the toner hopper and improves the stirring ability of the toner agitator during the replenishing operation. Furthermore,
An object of the present invention is to provide a developing device which ensures the safety of the user during the replenishment operation, does not cause toner scattering and agent drop, and saves power and has improved durability.

[0005]

In order to achieve the above object, the first invention of the present application is a toner cartridge having a shutter for dropping the toner contained therein through an opening on the lower surface, and the toner cartridge is detachable. In a developing device having a toner hopper having an opening on the upper surface, a toner agitator for sending the toner in the toner hopper to the toner replenishing section while stirring the toner in the toner hopper in association with the toner replenishing operation from the cartridge. Is rotatably supported and has a drive means for rotationally driving the toner agitator. In the second invention of the present application, the toner agitator driving means is means for rotationally driving the toner agitator by a toner replenishing operation by a pulling operation of a shutter on the lower surface of the toner cartridge. In the third invention of the present application, the toner agitator driving means is fixed to a rack gear formed on the lower surface of the shutter of the toner cartridge along the operation direction of the shutter, and a rotary shaft of the toner agitator in the toner hopper facing the rack gear. Characterized in that the toner agitator is rotationally driven by the engagement of the rack gear and the pinion gear by the pulling and pushing operation of the shutter. In the fourth invention of the present application, the toner agitator driving means has a magnetic plate formed on the lower surface of the shutter of the toner cartridge along the operation direction of the shutter, and rotates the toner agitator in the toner hopper facing the magnetic plate. The magnetic agitator is fixed to the shaft, and the toner agitator is rotationally driven by the engagement of the magnetic plate and the magnetic rotator by the pulling and pushing operation of the shutter.

According to a fifth aspect of the present invention, there is provided a first ratchet mechanism between the drive source of the developing device and the rotary shaft of the toner agitator, and between the drive source and the rotary shaft of the toner agitator caused by pulling and pushing the shutter. The second ratchet mechanism of the second ratchet mechanism is provided.

[0007]

In the developing device constructed as described above, only the toner agitator is rotationally driven in association with the toner replenishing operation during the toner replenishing operation, or the drive source of the toner agitator is pulled and pushed by the shutter to push the rack and pinion or With the magnetic plate and magnetic rotating body, the toner agitator performs the ratchet mechanism between the two drive sources, respectively, so that the toner in the toner cartridge is surely released into the toner hopper to loosen the toner during the replenishing operation. It is possible to obtain a developing device that produces the effect and improves the stirring ability of the toner agitator. Further, it is possible to obtain a developing device which secures the safety of the user during the replenishing operation, does not scatter toner, does not drop the developer, and saves power and has improved durability.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a side sectional view of a developing device to which the present invention is applied, FIG. 2 is a perspective view of a toner cartridge to which the present invention is applied, and FIG. 3 is a perspective view of essential parts of the developing device showing an embodiment of the present invention. is there. In the developing device 1 shown in FIG. 1, the toner in the toner tank is sent toward the first developing sleeve 5 by the rotation of the paddle wheel 3, and the amount of toner is fixed to the first developing sleeve 5 by the doctor 4 so as to reach the first developing sleeve 5. Sent, first
After being transferred from the developing sleeve 5 to the second developing sleeve 6, the toner is transferred to the photosensitive drum 2. The developer removed by the doctor 4 is laterally agitated by the separator 7 and the transport screw 8 and drops onto the elliptical plate 9, and is mixed with the developer returned from the second developing sleeve 6. When a control signal (not shown) receives a detection signal that the toner concentration is low, the toner replenishment brush 10 is rotated based on the detection signal to replenish the toner, and the elliptical plate 9 and the like mix and stir the developer. The new toner is stored in the toner hopper 11, and is sent onto the toner replenishing brush 10 by the toner agitator 12.

In FIG. 2, when the toner in the toner hopper 11 is used up, the toner cartridge 13 is mounted as shown in FIG. 1 and the shutter 14 is fully pulled in the pulling direction indicated by the arrow to drop the toner into the toner hopper 11. . The operation of toner replenishment is completed with the shutter 14 returned to the pushing direction, and then the toner cartridge 13 becomes a container for storing waste toner.

In FIG. 3, a developing device driving source 15 attached to an image forming apparatus (not shown) having two driving sources drives the entire developing device 1 via a clutch, and a driving force transmission path is provided in the developing device driving source 15. The agitator drive gear 16 located at the position drives the toner agitator 12. Further, a toner agitator drive motor (toner agitator drive means) 17 for independently driving only the toner agitator 12 is provided,
When the toner cartridge 13 is replaced, the motor 17
The control unit, which has received a toner cartridge set detection signal (not shown), rotates in response to an operation start command.
Stop by closing the door. Since the toner agitator 12 is constantly rotating during the toner cartridge replacement / replenishment operation, all the new toner in the toner cartridge 13 is transferred to the toner hopper 11. If the toner agitator 12 is stopped at the upper side, the toner is not completely lowered by the toner agitator drive motor 17 at the time of replenishing the toner, and the toner serves as a shielding plate.
At the end of the replenishment operation, a large amount of new toner remains in the toner cartridge 13. However, in this embodiment, all the new toner is supplied to the toner hopper 11 only by driving the minimum necessary toner agitator drive motor 17. Minimal power consumption.

FIGS. 4 and 5A and 5B are a perspective view of a main portion of a toner cartridge and a side sectional view and a front sectional view of the main portion of a developing device showing another embodiment of the present invention. 4 and 5 show
A rack and pinion system is shown as an alternative method of toner replenishment using the toner agitator drive motor 17. A rack gear 18 is formed on the lower surface of the shutter 14 in the operation direction, and a pinion gear 19 is arranged on the developing device 1 side so as to face the rack gear 18. The shaft of the pinion gear 19 is connected to the worm 20, and the opposing worm wheel 21 is connected to the toner agitator 12. The pinion gear 19 is rotated by pulling and pushing the shutter 14 at the time of replenishing new toner, and the worm 20
The worm wheel 21 is rotated via the, and the toner agitator 12 is rotated in conjunction therewith. According to this method, the toner agitator 12 is driven in synchronism with the toner replenishing operation, and since no electric power is used during this operation, power saving is achieved. The rack and the pinion form a toner agitator driving means.

FIGS. 6 (a) and 6 (b) are a side sectional view and a front sectional view of the main part of a developing device showing another embodiment of the present invention, in which the lower surface of the shutter 14 for opening and closing the opening of the lower surface of the toner cartridge 13 is shown. The magnetic plates 22 are arranged in the SN order in the operation direction, and the magnetic rotating bodies 23 arranged in the SN order in the surface rotation direction are provided on the opposite developing device 1 side to utilize mutual magnetic field action. The magnetic rotating body 23 is connected to the shaft of the worm 20, and the worm wheel 21 facing the magnetic rotating body 23 is connected to the toner agitator 12. Shutter 1 when replenishing new toner
The magnetic rotating body 23 rotates in response to the magnetic field of the magnetic plate 22 by the push-pull operation of 4, and the worm wheel 21 rotates via the worm 20.
To rotate. In this method, no electric power is required and the durability is good because the shutter 14 and the magnetic rotating body 23 are not in contact with each other. The magnetic plate 22 and the magnetic rotating body 23 are
It constitutes a toner agitator driving means.

FIG. 7 is a front sectional view of a main part of a developing device showing another embodiment of the present invention. If the pulling operation of the shutter 14 corresponds to the normal rotation direction of the toner agitator 12,
The other pushing operation is reverse rotation. However, this reverse rotation causes damage to the toner agitator 12 and adversely affects the drive system of the entire developing device 1. Therefore, the toner agitator 12 is provided with two ratchet mechanisms, that is, a first ratchet mechanism 24 and a second ratchet mechanism 25. During normal driving of the developing device 1, the normal rotating element of the agitator driving gear 16 is accurately transmitted to the toner agitator 12, and the reverse rotating element is canceled by the first ratchet mechanism 24. At the same time, the rotation of the toner agitator 12 is caused by the second ratchet mechanism 25 to rotate the worm wheel 21.
Will be canceled. During replenishment of new toner, the regular rotating element of the worm wheel 21 is accurately transmitted to the toner agitator 12, and the reverse rotating element is canceled by the second ratchet mechanism 25. At the same time, the rotation of the toner agitator 12 cancels the transmission to the agitator drive gear 16 by the first ratchet mechanism 24. Therefore, the two ratchet mechanisms, the first ratchet mechanism 2
4 and the second ratchet mechanism 25 can prevent the inconvenience of interfering the mutual driving, and further prevent the toner agitator 12 from rotating in the reverse direction.

[0014]

Since the present invention is configured as described above, only the toner agitator 12 is rotationally driven or the drive source of the toner agitator 12 is driven by the shutter 14 in association with the toner replenishing operation during the toner replenishing operation. The rack gear 18 and the pinion gear 19 or the magnetic plate 2 by pulling and pushing the
2 and the magnetic rotating body 23, the toner agitator 12
The first ratchet mechanism 24 is provided between the two driving sources.
And the second ratchet mechanism 25, so that the toner in the toner cartridge 13 is surely removed from the toner hopper 1.
Thus, the developing device 1 can be obtained in which the toner is agitated during the replenishing operation and the stirring ability of the toner agitator 12 is improved. Further, it is possible to obtain the developing device 1 which secures the safety of the user during the replenishing operation, does not scatter the toner, does not drop the developer, and saves electric power and has improved durability.

[Brief description of drawings]

FIG. 1 is a side sectional view of a developing device to which the present invention is applied.

FIG. 2 is a perspective view of a toner cartridge to which the present invention is applied.

FIG. 3 is a perspective view of a main part of a developing device showing an embodiment of the present invention.

FIG. 4 is a perspective view of a main part of a toner cartridge showing another embodiment of the present invention.

5A and 5B are a side sectional view and a front sectional view of a main part of a developing device showing another embodiment of the present invention.

6A and 6B are a side sectional view and a front sectional view of a main part of a developing device showing another embodiment of the present invention.

FIG. 7 is a front sectional view of a main part of a developing device showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Developing device, 2 ... Photosensitive drum, 3 ... Paddle wheel, 4 ... Doctor, 5 ... 1st developing sleeve, 6 ... 2nd developing sleeve, 7 ... Separator ,
8 ... Transport screw, 9 ... Elliptical plate, 10 ... Toner supply brush, 11 ... Toner hopper, 12 ...
Toner agitator, 13 ... Toner cartridge, 1
4 ... Shutter, 15 ... Developing device drive source, 16 ...
..Agitator drive gear, 17 ... Toner agitator drive motor, 18 ... Rack gear, 19 ... Pinion gear, 20 ... Worm, 21 ... Worm wheel, 22 ... Magnetic plate, 23. ..Magnetic rotating bodies, 24
... first ratchet mechanism, 25 ... second ratchet mechanism.

Claims (5)

[Claims] 1. A developing device having a toner cartridge having a shutter for dropping the toner accommodated therein from an opening on the lower surface and a toner hopper having an opening for attaching and detaching the toner cartridge on the upper surface, in the toner hopper. Is a rotatably supported toner agitator that sends toner toward the toner replenishing portion while stirring the toner in the toner hopper in conjunction with the toner replenishing operation from the cartridge, and a driving unit that rotationally drives the toner agitator. A developing device having. 2. The developing device according to claim 1, wherein the toner agitator driving unit is a unit that rotationally drives the toner agitator by a toner replenishing operation by pulling and pushing a shutter on the lower surface of the toner cartridge. 3. The toner agitator driving means is fixed to a rack gear formed on the lower surface of the shutter of the toner cartridge along the operation direction of the shutter, and a rotary shaft of the toner agitator in the toner hopper facing the rack gear. 3. The developing device according to claim 2, further comprising a pinion gear, wherein the toner agitator is rotationally driven by engagement of the rack gear and the pinion gear by pulling and pushing the shutter. 4. The toner agitator drive means has a magnetic plate formed on the lower surface of the shutter of the toner cartridge along the operation direction of the shutter, and has a rotating shaft of the toner agitator inside the toner hopper facing the magnetic plate. 3. The developing device according to claim 2, wherein the developing device comprises a fixed magnetic rotating member, and the toner agitator is rotationally driven by engagement between the magnetic plate and the magnetic rotating member when the shutter is pulled and pushed. 5. A first ratchet mechanism between the drive source of the developing device and the rotary shaft of the toner agitator, and a second ratchet mechanism between the drive source and the rotary shaft of the toner agitator caused by pulling and pushing the shutter. 5. The developing device according to claim 1, further comprising two ratchet mechanisms of the mechanism.