JPS5915954A - Developing device - Google Patents

Abstract

PURPOSE:To make a titled device small-sized and also to generate no toner blocking, by providing an opening on a partition wall of a developing device for holding a toner cartridge, and constituting said device so that a developer for replenishment is dropped down to a developing chamber by moving said partition wall. CONSTITUTION:As for a developing device partition wall 5 for holding a toner cartridge 4, many conical holes 5a are provided on an area facing its rectangular opening 4a when the toner cartridge 4 is inserted to the inner part, and when a toner shortage signal is inputted to a controlling circuit, the partition wall 5 and the toner cartridge 4 execute a half rotation together and come to a standstill. In this case, the opening 4a of the toner cartridge 4 turns downward, therefore, a toner drops down into a developing chamber from many conical holes 5a formed on the partition wall 5. The conical holes 5a are perforated at equal intervals in the direction of a developing sleeve shaft, therefore, the toner is supplied uniformly in the direction of the developing sleeve shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device which is applied to an image forming apparatus such as an electrophotographic copying machine or an electrostatic recording machine and which visualizes a latent image formed on an image carrier.

Conventionally, a simple and common method for replenishing toner for this developing device (hereinafter also referred to as a developing device) is to open nine bags and drop the toner into the developing device. However, with this replenishment method, the toner scatters violently during replenishment, causing troubles such as staining the operator's hands and clothes, making the operation unpleasant.

Therefore, in order to alleviate this problem, it has been considered to use a cylindrical toner cartridge. This toner cartridge has its opening facing upward, peels off the tape blocking the opening, inserts it into the developing device from the front side, and when it is fully inserted, rotates it 180 degrees around the central axis of the cylinder, and with the opening facing downward, removes the tape blocking the opening and inserts the toner cartridge. The toner is dropped into the developing device, and the above-mentioned trouble does not occur because the toner falls in a closed space. However, this cartridge-type developing device requires a cartridge housing space in addition to the toner storage space, which has the disadvantage that the developing device becomes large. Furthermore, this is not limited to cartridge-type developing devices, but includes a developing sleeve (description will be given later) and a partition plate that is provided at a small distance from the developing sleeve in order to regulate the amount of toner adhering to the developing sleeve. The toner between the toner and the toner is subject to a large amount of pressure due to the weight of the toner at the top and because it is passed through a small gap, and the disadvantage is that it is easy to block. It was difficult to put this method into practical use with toners used in fixing systems.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing device which eliminates the above-mentioned drawbacks and is compact and free from toner blocking.

Hereinafter, nine embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional front view showing the first embodiment, FIG. 2 is a perspective view of a toner weight supply section, and FIG. 6 is an enlarged sectional view of a toner drop hole section. Reference numeral 1 denotes a photosensitive drum as an image bearing member, 2 a developing device, 6 a nozzle for the developing device, and 4 a toner cartridge inserted into the developing device 2 in the direction of arrow A, and an opening 4a for replenishing toner.

A protrusion 4b is provided for accurately inserting the toner cartridge. Reference numeral 5 denotes a developer partition wall that holds the toner cartridge 4, and has a large number of conical holes 5a in an area facing the rectangular opening 4a when the toner cartridge 4 is fully inserted. Further, a recess 5b is provided corresponding to the projection 4b, and the toner car (IJ) is restrained by the partition wall 5 against movement in the direction of arrow B.

Six bearings rotatably support the partition walls 5, and their outer peripheries are fixed to the housing 3. A seal member 7 prevents toner from entering the bearing 6. It is a fan-shaped swinging plate having a gear 8at that meshes with a gear 5C formed at the rear end of the 8-shaped bulkhead 5, and a portion corresponding to the key point of the fan is connected to the shaft 9a of the rotary solenoid 9 fixed to the rear side plate 6b of the developer. Fixed. Reference numeral 10 denotes a developing sleeve made of a non-magnetic material that is arranged in parallel with the photosensitive drum 1 with a gap g1, and is rotatably supported in the direction of the arrow, and a magnet 11 having a plurality of magnetic poles is housed inside the sleeve. 12 is the gap g2 where the lower tip of the developing sleeve 10 is determined? With the forming partition plate.

Together with the housing back plate filter C, the toner storage chamber (hereinafter referred to as the toner storage chamber).

(referred to as hopper) 13. A recess 6d is formed in the center of the back plate 6C, with both sides parallel to each other and protruding backwards.As shown in FIG. 4, a lamp L and a light receiving element P are provided to sandwich both sides of the recess 6d from the outside. A photocoupler 14 is provided.

This is because the first embodiment of the present invention has the above configuration.

The toner T in the hopper 13 is removed from the opening 1 at the bottom of the hopper.
3a to the surface of the developing sleeve 10.

The developing sleeve 10 is attracted to the surface of the sleeve rotating counterclockwise by the magnetic force of the magnet 11 having a plurality of magnetic poles and is carried. Here, the lower end of the partition plate 11 is bent toward the developing sleeve 1L; 0 side, and a predetermined gap g2 is formed between the partition plate 11 and the developing sleeve 10, so that the toner on the sleeve 10 is restricted. has been done. The toner on the developing sleeve 10 comes into contact with the surface of the photosensitive drum 1 at the position where the sleeve is closest to the photosensitive drum 1, and develops the electrostatic latent image on the photosensitive member. When the toner in the hopper 16 decreases due to repeated development, the toner buried in the recess 3d of the back plate 3C is also attracted to the sleeve side by the magnetic force.
A photocoupler 14 arranged to sandwich this recessed portion d detects that the amount of residual toner has fallen below a set value,
The toner shortage signal is input to a control circuit (not shown). In response to this signal, the control circuit excites the rotary solenoid 9 and applies a rotational force to its shaft 9a, so that the fan-shaped swing plate 8 connected to the shaft 9a rotates by a specified angle in the direction of arrow C and comes to rest. At the same time, the partition wall 5 and the toner cartridge 4 rotate by half a rotation due to the gear 5cK meshing with the gear of the rocking plate 8 and come to rest. At this time, the opening 4a of the toner cartridge faces downward, and the toner falls through a large number of conical holes 5a formed in the partition wall 5. Since the conical holes are equally spaced in the axial direction of the developing sleeve, toner is uniformly replenished in the axial direction of the developing sleeve. After a certain period of time, when the control circuit demagnetizes the rotary solenoid 9, its shaft 9a is returned to its original state by the built-in return spring, and the rocking plate 8 attempts to return to its initial state, causing the partition wall supported to rotate nine times. , return the opening for toner replenishment to the upper position again.

When toner is refilled several times and the amount of toner in the toner cartridge becomes small, the replenishment interval time becomes shorter, so compare this with the specified time and when the time falls below the specified time,
A signal from the control circuit is used to display an external display indicating that toner is insufficient or to stop the operation of the device.

It is also clear from the hourglass principle that the rate at which particulate matter falls through the small diameter hole is constant regardless of the amount of particulate matter in the upper chamber. Therefore, this embodiment is extremely effective as a means for quantitatively replenishing toner particles.

In the first embodiment, the toner cartridge receiving member and the partition wall are integrated, and the partition wall is rotated together with the toner cartridge. However, as shown in FIG. 5, the toner cartridge 4 is rotatably held, A seal L-shaped partition 5 is provided in close contact with the lower surface of the toner cartridge, one end of the partition sheet is fixed to the take-up shaft 30, and the gear 61 at the radial end of this shaft is engaged with the gear 8a of the swing plate 8. The partition wall opening may be configured to be moved. In this example.

When the rotary solenoid 9 is excited by the toner shortage signal, a claw (
(not shown) is removed, and as the partition sheet 5 moves, the cartridge opening also rotates due to the frictional force with the partition sheet, and the two openings 4a and 58 align directly above the developer storage section, allowing the toner T to fall and be replenished. It will be done. After a predetermined period of time has elapsed, when the rotary solenoid 9 is demagnetized, the partition sheet is restored by the spring 32 at the other end of the partition sheet, and the partition opening also returns to its original position. At the same time, the toner cartridge also rotates back, opening 5a returns upward, and nine rotation regulating claws are engaged.

Further, in this embodiment, the toner shortage is detected by the sensor 14 provided in the developing device, but the present invention is not limited to this, and a sensor may be provided in a location other than the developing device to detect the toner shortage.

Another embodiment shown in FIG. 6 has a small diameter hole or slit opening 21at in the case of the toner cartridge 21. established,
The partition wall function in the above embodiment is provided in the case of the toner cartridge. That is.

The toner cartridge 21 has a recess 21b on the outer surface of its case.
and the convex part 22a provided at the entrance of the toner cartridge receiving part 22 of the developing device, and move it in the direction of arrow A to install it in the receiving part 22. At this time, the opening 21a faces toward the road. When the toner cartridge 21 is inserted to a predetermined position, a convex portion 21c on the rear end surface of the toner cartridge engages with a concave portion 23a of a rotating ring 23, which will be described later, and the spinning end of the toner cartridge is fixed to the IJ socket 22 (toner car). It is supported by a bearing 24a. In this supported state, the convex portion 22a of the toner cartridge receiving portion engages with the small diameter portion 21d of the toner car IJJ joint portion, thereby forcing the toner cartridge 21 to be rotatable.

The rotating ring 23 is rotatably held by a bearing 24b fixed to the rear of the toner cartridge receiving portion 22.

A gear 23b is formed on the outer peripheral surface of the rear end! - It meshes with a gear 8a formed on the arc portion of the fan-shaped swing plate 8. A portion of the swing plate 8 corresponding to the fan is fixed to a shaft 9a of a rotary solenoid 9 fixed to the rear side plate 3b of the developing unit. (toner car) There is no lower upper wall surface of the IJ socket, and the space of the hopper 16 formed by the partition plate 12 and the housing back plate 3C is connected to the space of the toner cartridge receiving part. Incidentally, the small diameter portion 21d at the front portion of the toner cartridge may be formed to have a substantially semicircular shape as shown in FIG.

In the above configuration, when the rotary solenoid 9 is excited by the toner shortage signal, the swing plate 8 fixed to the shaft 9a rotates in the direction of arrow C and comes to rest. At the same time, the rotating ring 23 supported by the bearing 24b and the toner cartridge 21 supported by the rotating ring 23 and the bearing 24a rotate half a rotation by the gear 26b that meshes with the gear 8a of the rocking plate, and then come to rest.

At this time.

The opening 21aH of the toner cartridge faces downward.

A certain amount of toner falls.

As explained above, a partition wall is provided that divides the toner storage chamber into two upper and lower parts, and a toner shortage signal is received from the small diameter hole or slit-shaped opening formed in the partition wall to allow the toner to fall for a certain period of time. can be easily realized, and the amount of toner in the hopper can be controlled to be less than a specified amount without causing toner blocking. Conventional by doing this.

This also reduces toner blocking in the gap between the developing sleeve and the partition plate, where toner blocking was likely to occur.

Therefore, it can be used stably even for toner used in a pressure fixing method with excellent energy saving properties.

Furthermore, since the toner cartridge serves as a toner storage chamber, a part of the conventional hopper can be made smaller, so that the developing device can be made smaller. Further, since the toner is replenished by gravity, the toner may be either magnetic or non-magnetic.

The method of rotating the toner cartridge and moving the opening direction of the conical hole up and down has the effect of flattening the toner in the toner cartridge and can replenish the toner uniformly. Further, by obtaining the driving force for one rotation from a rotary solenoid provided in the developing device, it is effective against a power failure during toner replenishment. If rotational movement outside the developing device is received through a clutch, it is difficult to take measures against the case where the opening faces downward during toner replenishment and the opening does not return when the power is turned off.

Furthermore, by providing the toner cartridge case with the function of a partition wall, troubles caused by toner clogging in small-diameter holes and slit-shaped openings are reduced. The reason for this is that compared to the case where a small-diameter hole or slit-shaped opening is provided in the developing device, the opening is also replaced with a new one every time a new toner cartridge is replaced. Furthermore, even if blindness occurs, recovery is extremely easy.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional front view showing a first embodiment of the developing device of the present invention;
FIG. 2 is a perspective view showing a fixed amount toner replenishing section. FIG. 3 is an enlarged sectional view of a portion of the toner supply hole, FIG. 4 is an enlarged sectional view of a remaining toner amount detection section, and FIG. FIG. 6 is a perspective view showing another embodiment of the fixed amount toner supply section;
Figure 7 shows the toner car in the embodiment shown in Figure 5)
FIG. 7 is a perspective view showing another shape of the front part of the J-shaped hinge. 2 is a developer, 4 and 21 are toner cartridges. 5 is a developer partition, 5a is a conical hole, and 6 is a bearing. 8 is a rocking plate, and 9 is a rotary solenoid. 14 is 7 Otokapura.

Claims (1)

[Scope of Claims] (1) A developing chamber, a replenishment developer storage chamber adjacent to the upper side of the developing chamber and partitioned by a movable partition, and a means for driving the partition; is provided with an opening for dropping replenishment developer in the storage chamber into the developing chamber, and the core opening is located at a first position facing the opening of the developing chamber as the partition wall is moved by the driving means, and at a first position facing the opening of the developing chamber. A developing device characterized in that it is configured to take a second position in which the developing device does not operate. (2) The developing device according to claim 1, wherein the partition wall is configured in a cylindrical shape, and the movement thereof is a rotational movement approximately centered on the inner axis of the cylinder. (b) The developing device according to claim 1 or 2, wherein the partition wall is removable. (4) Any one of claims 1 to 6, wherein the dimensions of the opening are determined so that when the opening faces the developing chamber, the amount of replenishing developer falling per hour is approximately equal. or1
Developing device described in Section 1. (5) The developing device according to any one of claims 1 to 4, wherein a plurality of openings are arranged substantially parallel to the developing width direction. (6) The developing device according to any one of claims 1 to 4, wherein the opening is a long hole substantially parallel to the developing width direction. (7) A replenishment developer cartridge having an opening can be removably installed in the storage chamber, and when at least the opening of the partition wall is in the first position, the replenishment developer cartridge) The opening of the IJ joint is also in the first position. A developing device according to any one of claims 1.2.4 to 6, configured as described in claim 1.2.4.