JPH0256671B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a toner replenishing device for electronic copying machines, printers, and the like.

"Prior Art" For example, in an electronic copying machine, an image is created using a drum-shaped or belt-shaped photoreceptor through the steps of charging, forming an electrostatic latent image, developing, transferring, and fixing.

Some of the developing devices of such electronic copying machines are designed to perform development by a magnetic brush development method using a two-component developer consisting of toner and a magnetic carrier that conveys the toner.

FIG. 1 shows an example of a conventional developing device. This developing device includes a developing device main body 2 provided opposite to a drum-shaped photoreceptor 1. Although not shown, a developer consisting of toner and a magnetic carrier for conveying the toner is stored in the developing device main body 2 . Developing device main body 2
A magnet roll 3 is provided at a predetermined location facing the photoreceptor 1 inside. A developer regulating plate 4 is provided at a predetermined location facing the magnet roll 3. Further, a developer stirring/supplying wheel 5 is provided at another predetermined location facing the magnet roll 3.

The developer in the main body 2 of this developing device is first picked up onto the surface of the magnet roll 3 by the wheel 5 rotating in the direction of the arrow. The picked up developer is conveyed by the rotation of the magnet roll 3 in the direction of the arrow, and is controlled by the regulating plate 4 to an optimum amount. After this, the developer is applied to the development area (the part closest to the photoreceptor 1 and the magnet roll 3).
A brush-like spike is formed slightly in front of. The toner in this brush-like developer adheres to the electrostatic latent image formed on the surface of the photoreceptor 1 rotating in the direction of the arrow, and development is performed. The developer remaining on the surface of the magnet roll 3 is picked off at a predetermined location and collected near the wheel 5.

This developing device is equipped with a toner replenishing device 11 for automatically replenishing toner in response to consumption of toner in the developer during the developing process. The toner replenishing device 11 includes a toner box 12 (not shown) containing toner.
The toner box 12 is provided at the upper part of the developing device main body 2. The toner box 12 is shaped like a hopper, and a rotating body 13 for replenishing toner made of a urethane foam, a brush, or the like is provided at the bottom thereof. In this toner replenishing device 11, when the developer in the developing device main body 2 decreases to some extent due to toner consumption, a sensor (not shown) detects this and rotates the rotating body 13 in the direction of the arrow. As a result, the toner in the toner box 12 is appropriately replenished into the developing device main body 2. Toner box 1
When the remaining toner in the toner 2 becomes low or disappears, an operator or a service person will replenish the toner.

Incidentally, in such a toner replenishing device, a rotating body 13 consisting of a urethane platform or a brush is used.
Toner is replenished by the simple rotation of the toner, so if the toner sticks together and clumps together due to the type of toner or environmental conditions, the amount of toner supplied will decrease and the density of the image will decrease. It had the disadvantage of being stored away.

FIGS. 2 and 3 show an example of a conventional toner replenishing device that eliminates such drawbacks. A hopper-shaped toner box 21 is fixed to a frame 22. A threaded rod 23 is rotatably provided in the lower part of the toner box 21. A toner replenishment port 2 is provided at a location corresponding to one end of the threaded rod 23 at the center of the lower part of the toner box 21.
4 is provided. Shaft 25 of threaded rod 23
One end is rotatably attached to one frame 22. The other end of the shaft 25 is attached to a gear 26 rotatably provided on the other frame 22. The gear 26 is connected to an output shaft 28 of a motor 27 attached to the frame 22 via a mounting member (not shown). Threaded rod 2
At a predetermined location in the toner box 21 above the toner box 3, a stirring member 31 is provided which is formed by appropriately bending a rod. One end of the stirring member 31 is rotatably attached to one frame 22 via a ring 32. The other end of the stirring member 31 is
It is attached to a gear 33 rotatably provided on the other frame 22. The rotation center of the stirring member 31 is parallel to the rotation center of the threaded rod 23. The gear 33 is meshed with the gear 26.

In this toner replenishing device, when the motor 27 is driven, the threaded rod 23 and the stirring member 31 are each slowly rotated in a predetermined direction. Threaded rod 23
When the toner is rotated, the toner in this portion is conveyed in the direction of arrow A, and is appropriately replenished into the developing device main body (not shown) from the toner replenishing port 24. When the stirring member 31 is rotated, the toner in the toner box 21 is appropriately stirred and is prevented from sticking together and clumping together.

By the way, in such a toner replenishing device, since the stirring member 31 is provided above the threaded rod 23, the toner in the valley of the threaded rod 23 and its vicinity is not stirred. For this reason, threaded rod 2
There were cases where the toner stuck to each other and solidified at or near the valley of No. 3. Particularly in the case of high humidity, the toner sometimes hardens around the threaded rod 23, creating a tunnel.

"Problems to be Solved by the Invention" The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toner replenishing device that can effectively prevent toner from sticking to each other and clumping together. do.

"Means for Solving the Problem" In the present invention, a plurality of protrusions are provided on the toner agitation member provided above the threaded rod at the same pitch as the threads of the threaded rod, and these protrusions can be made to enter the valleys of the threaded rod. The threaded rod and the toner stirring member are rotated in synchronization with each other, thereby stirring the toner in the valley of the threaded rod and in the vicinity thereof.

"Example" The present invention will be explained in detail with reference to Examples below.

4 and 5 show the main parts of a toner replenishing device in one embodiment of the present invention. In these figures, parts with the same names as in FIGS. 2 and 3 are designated by the same reference numerals, and their explanations will be omitted as appropriate.

The agitating member 31 of this toner replenishing device has a plurality of acute-angled protrusions 41 that protrude at the same pitch as the threads of the threaded rod 23, and is designed to allow these to enter the valleys of the threaded rod 23 as appropriate. It's summery.
Further, the number of teeth of the gears 26 and 33 are both the same. As a result, the stirring member 31 is rotated in synchronization with the threaded rod 23.

Therefore, in this toner replenishing device, when the motor 27 is driven, the threaded rod 23 and the stirring member 31 are rotated slowly in predetermined directions in synchronization with each other. At this time, the protruding portion 41 of the stirring member 31 is appropriately inserted into the valley of the threaded rod 23 without interfering with the threaded portion. As a result, the toner in the valley of the threaded rod 23 and its vicinity is also appropriately agitated.

[Effects of the Invention] As explained above, according to the present invention, it is possible to stir the toner in the valleys of the threaded rod and in the vicinity thereof, so that it is possible to effectively prevent the toner from sticking to each other and clumping together. Therefore, toner is stably supplied into the developing device main body, and the image density can be maintained at a specified value.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an example of a developing device in a conventional electronic copying machine, FIG. 2 is a longitudinal sectional side view showing another example of a conventional toner replenishing device, and FIG.
FIG. 4 is a longitudinal sectional view taken along line - in the figure, FIG. 4 is a longitudinal sectional side view showing the main parts of a toner replenishing device in an embodiment of the present invention, and FIG. 5 is a longitudinal sectional view taken along line V-V in FIG. 4. It is. 21... Toner box, 23... Threaded rod, 2
4...Toner supply port, 26, 33...Gear, 27
... Motor, 31 ... Stirring member, 41 ... Projection.

Claims (1)

[Claims] 1. A toner box provided at the top of the developing device main body and having a toner replenishment port at a predetermined location at the bottom; and a toner box provided at the bottom of the toner box that rotates to convey the toner in the toner box to the toner replenishment port. A threaded rod, provided above the threaded rod so as to be rotatable about an axis parallel to the axis of rotation of the rod, and having a plurality of protrusions protruding at the same pitch as the threads of the threaded rod, A toner replenishing device comprising: a toner agitating member that enters into the valley of the rod; and a drive mechanism that rotates the threaded rod and the toner agitating member in synchronization with each other.