JPS6383758A - Developing device - Google Patents

Abstract

PURPOSE:To prevent a bridge by moving a device by a partition provided between 1st and 2nd toner chambers, a remaining toner detection means moving due to the turn of a toner supply means, and another remaining toner detection means which is astride the two chambers and positioned on their bottom sides. CONSTITUTION:Toner feeder moving means 38 whose ends are supported swingingly or slidably are provided on the bottoms of the 2nd and 1st toner chambers 35 and 33. The partition 34 and the toner feeder moving means 38 form a toner replenishment path 39. The toner supply means 36 is constituted of a rotatably journaled agitation and supply member 36a consisting of a leaf or a crank bar. The remaining toner detection means has a swingingly journaled arm 37b, and is constituted to a detection member 37a provided so that it can reciplocatingly move between a 1st position in the upper part and a 2nd position in the lower part in the 1st toner chamber 33, and a detection means detecting that the detection member 37a reaches the 2nd position. If toner in the 1st toner chamber 33 becomes empty, the effect is displayed to the outside. Thus toner can be supplied without developing the bridge.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a dry developing device used in electrophotographic copying processes and the like.

BACKGROUND OF THE INVENTION As dry developing methods that have already been put into practical use, there are a one-component developing method using a developer made of only magnetic toner and a two-component developing method using a developer made of a mixture of a magnetic carrier and toner. -The component development method has the advantage of simplifying the developing device, making it smaller and lowering the price, but the toner requires contradictory conditions such as conductivity during development and insulation during transfer. Currently, toners with high resistance, which do not place much burden on the copying process and have good transfer characteristics, are used, and various measures are taken to improve the development characteristics. In the two-component development system, even though the developer is originally a -component developer, magnetic carrier is mixed in to ensure triboelectric charging of the toner, increase in conveyance force by improving magnetic permeability, etc., and the development and transfer characteristics of the toner itself are improved. Although this method is good, it has drawbacks such as the development device becoming complicated and large.

As one measure to eliminate these drawbacks, a dry developing method was devised in which magnetic carrier is mixed into the toner layer on the outer peripheral surface of the developing roller for development, as shown in Figure 2.
A developing sleeve 2 having a magnetic roller 1 inside and for transporting magnetic developer in one direction on its outer peripheral surface, and an outer peripheral surface of the developing sleeve 2 located on the upstream side of the developing area X in the developer transporting direction (arrow). The empty chamber 3 opens toward the direction of the developing sleeve 2 and is filled with a magnetic carrier or a mixture of magnetic carrier and toner in advance. a toner supply slit 5 that communicates between the toner supply tank 4 and the toner supply tank 4; and a toner supply means 6 that supplies the toner 8 contained in the toner supply tank 4 into the empty chamber 3 through the toner supply slit 5. It has been proposed as a dry developing device equipped with
(See Publication No. 3677).

In this dry type developing device, first, a magnetic developer 7 made of a mixture of magnetic carrier and toner is loaded into a vacant chamber 3, and a magnetic toner 8 is loaded into a toner replenishing tank 4. The developer 7 in the empty chamber 3 is circulated and conveyed in the direction of the arrow C by the rotation of the developing tube IJ-tub 2 in the direction of the arrow A and the rotation of the magnetic roller 1 in the direction of the arrow a. The electrostatic latent image carried on the surface of the rotating photoreceptor drum 9 is developed. After being subjected to development, the magnetic developer remaining on the outer peripheral surface of the developing sleeve 2 is transferred to the empty chamber 3 again, where new magnetic toner is supplied, mixed and stirred within the empty chamber 3, and then developed again. served. The magnetic toner 8 stored in the toner supply tank 4 is conveyed to the toner supply slit 5 side by the rotation of the toner supply blade 6 in the direction of the arrow d, and is conveyed to the toner supply slit 5 side by the rotation of the magnetic roller 1 in the direction of the arrow a. The toner rises due to the pulsating action and is supplied into the empty chamber 3 through the toner supply slit 5.

The supply amount corresponds to the amount of toner reduced in the empty chamber.

A known method for replenishing toner is to rotate a windmill installed at the opening of the toner replenishing tank, but due to the poor fluidity of the toner itself and its low specific gravity, the toner does not flow easily and the toner does not flow easily. It has the disadvantage that toner replenishment tends to become uncertain due to toner remaining at the bottom of the tank, bridging at the opening, or clogging the groove of the wind turbine.

As one of the measures to eliminate such defects, as shown in FIG. This causes the toner to flow without bridging or remaining at the bottom of the toner tank 11, and the tip 1211L of the diaphragm 12 quickly moves in contact with the flat part of the windmill 13, so that the flat part 13? A toner replenishing device has been proposed that removes the toner 14Q remaining in the toner L and replenishes the toner in a fixed quantity (see Japanese Utility Model Publication No. 4919/1983).

Problems to be Solved by the Invention By the way, in the above-mentioned developing device (Japanese Unexamined Patent Publication No. 81-53677), when replenishing toner from the toner replenishing tank 2 to the developer chamber 1, the toner supply blade 6 supplies toner 8. The chamber in which the operation of stirring the toner 8 and supplying the toner 8 to the toner supply slit 7 is performed and the toner supply tank in which the toner is stored and replenished as necessary are in the same room.
Depending on the amount of toner 8 in the toner replenishing tank 2, a difference will occur in the supply pressure of the toner 8 along with fluctuations in the required stirring force of the toner supply blade 6, resulting in a difference in toner concentration.

In addition, in the above toner replenishing device (Japanese Utility Model Publication No. 61-4119), the vibration stroke may be affected by slight variations in the shape and mounting position of the wind turbine 13, the dimensions and mounting position of the diaphragm 12, or the deflection of the diaphragm 12. The toner density may vary, and sometimes it may not vibrate, resulting in a difference in toner density.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to supply toner in an amount commensurate with consumption, to eliminate toner from remaining at the bottom of the toner chamber, and to supply toner in a single line without causing any bridging.

Means for Solving the Problems The developing device according to the present invention includes a first toner chamber having toner supply means for agitating and supplying toner, a second toner chamber for storing and replenishing toner, and first and second toner chambers. It consists of a partition member that partitions the toner chamber, and a toner replenishing means that supplies toner from the second toner chamber to the first toner chamber.

When the working toner is consumed, the toner in the first toner chamber is supplied through the toner supply slit. The toner is conveyed to the toner supply slit side by the toner supply means in an amount corresponding to the supplied amount of toner. Toner is replenished from the second toner chamber according to the amount of toner in the first toner chamber, which prevents differences in toner concentration and prevents toner remaining at the bottom of the second toner chamber by the movable operation of the toner replenishing means. is also prevented.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In FIG. 1, a rotatable magnetic roll 22 having a plurality of magnetic poles is contained in a housing 21 of a developing device, and a sleeve with a rough surface made of a non-magnetic material and rotatable relative to the magnetic roll 22 is shown. A developing roller 24 consisting of a developing roller 23 is disposed close to the surface of the photosensitive drum 250.

The developer 26 is held and conveyed on the outer peripheral surface of the sleeve 23 in the direction indicated by the arrow A by the rotation of the magnetic roll 22 in the direction of the arrow a and the rotation of the sleeve 23 in the direction indicated by the arrow. In order to regulate the layer thickness of the developer 26 on the surface of the sleeve 23 held and conveyed in the development area X direction, the developer 26 is located upstream of the development area The layer thickness regulating member 27 is fixedly installed on the developer guiding member 28 . The developer guide member 28 is attached to the housing 21 . The regulating plate 29 is disposed to extend in the axial direction of the sleeve 23 so as to face the surface of the sleeve 23 on the upstream side of the layer thickness regulating member 2 in the developer transport direction, and is arranged to extend in the axial direction of the sleeve 23 so as to regulate the layer thickness of the housing 21° and the developing roller 241. The member 27 and the support member 28 form a developer chamber 30 within the magnetic field area of the magnetic roll 22 to accommodate the developer conveyed by the developing roller 24. The guide plate 31 extends in the axial direction of the sleeve 23 on the upstream side of the developer chamber 3o in the developer transport direction, has a tip end protruding into the developer chamber 3o, and has a distal end with respect to the surface of the sleeve 23 and the lower end of the regulating plate 29. Each is arranged with a predetermined gap,
It is attached to the bottom of the housing 21. A toner supply path 32 is formed near the lower end of the regulation plate 29 and the guide plate 31 .

A first toner chamber 33 for storing toner and a second toner chamber 36 partitioned by a partition plate 34 above the first toner chamber 33 are provided behind the toner supply path 32 . First toner chamber 33
Inside, a toner supply means 36 for stirring the toner and supplying it into the toner supply path 32, and a remaining toner amount detection means 37 for detecting empty toner are installed. At the bottoms of the second toner chamber 36 and the first toner chamber 33, a toner feeding movable means 38 whose one end is swingably or vibrably supported is provided. A supply path 39 is formed. The toner supply means 36 includes an agitation supply member 361 rotatably supported using a blade plate, a crank rod, or the like.
It is composed of etc. The remaining toner amount detecting means has an arm 37b that is pivotally supported in a swinging manner, and
A detection member 3a is provided to be able to swing back and forth between a first position at the inner upper part and a second position at the lower part thereof, and a detection member 37a is periodically abutted against the arm 37b to extend the detection member 37a to the first position. The agitation supply member 362L is used as a regulating means for side movement, and the biasing means is used to properly balance the weight of the arm 37b and the detection member 3A to bias the detection member 3A to the second position. (not shown) and a detection means (not shown) that uses a switching means to detect when the detection member 37& is located at the second position, and when the toner in the first toner chamber 33 becomes empty, the toner is Is displayed.

The rocking or vibration of the toner feeding movable means is caused by regular contact with the one end 370 of the remaining toner amount detection member 3a and the bottom surface 2.
1 and an elastic member 40 provided between the two. Note that the toner feeding movable means 38 can also be constructed of a sheet-like material such as polyester or polyethylene.

Next, the operation of the developing device having the above configuration will be explained.

First, a developer consisting of a mixture of a magnetic carrier and a magnetic toner is loaded into the developer chamber 3o, and after the device is pre-operated, the first toner chamber 33 and the second toner chamber 35 are loaded with a developer containing the magnetic toner 8. agent is loaded. At this time, developer chamber 3
Only the magnetic carrier may be loaded into the 0. In addition, in the case of one-component development using only a magnetic toner developer without using a magnetic carrier, the second. Toner may be loaded into the developer chamber 30 through the first toner chambers 35 and 33. and,
In this state, the electrostatic latent image can be developed by this device.

Here, the developer is held and conveyed on the outer peripheral surface of the sleeve 23 in the direction indicated by the arrow A by the rotation of the magnetic roll 22 in the direction of the arrow a and the rotation of the sleeve 23 in the direction indicated by the arrow. When passing through the developer chamber 30, the magnetic carrier and magnetic toner are mixed and stirred, and each is triboelectrically charged. As a result of this mixing and agitation, the magnetic carrier, which is the developer, and the magnetic toner are constantly integrated at a mixing ratio within a certain range at this point, and a magnetic brush made of the developer is reliably formed in the development area. Ru.

The magnetic brush formed here rubs the surface of the photoreceptor drum 26, and develops the electrostatic latent image on the surface into a visible image. After being subjected to development, the developer remaining on the outer peripheral surface of the sleeve 23 reaches the developer chamber 3o again, where it is mixed and stirred with the toner supplied from the first toner chamber, and then subjected to development again. . At this time, since the developer in the developer chamber 30 is always attracted toward the surface of the sleeve 23 by the magnetic force of the magnetic roll 22, the rotation of the developer roller 24 causes the developer near the surface of the sleeve 23 to move in the direction of arrow d. The remaining developer is regulated by the layer thickness regulating member 27 and flows in the direction of the arrow e, and is mixed and stirred uniformly throughout, and its flow in the axial direction of the sleeve 23 is suppressed.

Toner is supplied to the developer chamber as follows.

The toner stored in the first toner chamber 33 is conveyed to the toner supply path 32 side by the rotation of the agitation supply member 36'a- in the direction of arrow f, and is conveyed to the toner supply path 32 side by the rotation of the magnetic roll 22 in the direction of arrow a. Due to the pulsating action, the toner rises along the surface of the guide plate 31 on the regulating plate 29 side, and is supplied into the developer chamber 3o through the toner supply path 32. The supplied amount corresponds to the amount of toner reduced in the developer chamber 3Q.

The toner 8 stored in the second toner chamber 35 is shaken by contact with one end 370 of the detection means 37, which is rotated back and forth between the second position and the first position by the agitation supply member 36N. The toner is replenished into the first toner chamber 33 through the toner replenishment path 39 by the forward movement arrow g of the toner feeding movable means 38, which is moved or vibrated, toward the toner chamber bottom surface 212L, and by the backward movement arrow g of the elastic member 4o. Ru. The amount of toner to be supplied is replenished in accordance with the internal pressure within the first toner chamber 33, and a space 33& is always maintained in the upper layer of the first toner chamber 33.

As the toner in the second toner chamber 35 runs out, the toner in the first toner chamber 33 decreases. As the amount of toner decreases, the swing of the detection means 37 increases, and the detection member 371L
is moved down to the second position and swung, the second. Empty toner in the first toner chamber 35, 33 is detected and displayed externally.

Further, as the developing bias, a direct current voltage may be applied to the sleeve 23 based on a normal method, an alternating current voltage may be superimposed thereon, or the sleeve 23 may be grounded.

By the way, when this device was used, no unevenness in toner concentration occurred in the axial direction of the sleeve 23 even after long-time operation. Furthermore, even when the device was operated with the sleeve 23 tilted at an angle of about 57,100 rran in the axial direction, the toner density could be maintained within a certain range that ensured high quality images. This is because the developer in the developer chamber 30 is always attracted toward the surface of the sleeve 23 by the magnetic force of the magnetic roll 22, so that it is uniformly mixed and stirred as a whole, and the developer is not only mixed and stirred in the axial direction of the sleeve 23. This is because the flow, especially the flow of magnetic carriers, is suppressed.

Further, the toner supply path 32 is filled with toner,
This toner is subjected to pressure (supply force) in the direction of the developer chamber 30 due to the magnetic field effect caused by the rotation of the agitation supply member 361L of the toner supply means 36 and the rotation of the magnetic roll 22, so that the toner does not flow into the 11th toner chamber 33. This is because the outflow of the developer, especially the outflow of the magnetic carrier, can be suppressed. Furthermore, the toner supplied to the developer chamber 30 is not immediately supplied onto the surface of the sleeve 23, but is mixed and stirred within the developer chamber 3o, so that the developer is sufficiently charged and the development bias is adjusted. The application works effectively and high quality images without fogging etc. can be obtained. By maintaining the toner concentration in the developer chamber 3o constant, the toner concentration of the developer forming the magnetic brush in the development area X is always constant. In the present invention, only the consumed amount of the developer in the developer chamber 30 is supplied to the developer chamber 3o, and the toner concentration in the developer chamber 3o is substantially constant. Therefore, automatic toner concentration control based on volume control is possible.

Effects of the Invention As is clear from the above explanation, according to the present invention, there is a developer chamber that stores the developer held and conveyed by the developing roller within the magnetic field area of the magnetic roll, and a sleeve on the upstream side of the developer chamber. a guide plate that extends in the axial direction and is disposed with its tip end protruding into the developer chamber to form a supply path for supplying toner to the developer chamber; and a toner supply means for supplying toner into the supply path. a first toner chamber having a first toner chamber; a second toner chamber for replenishing toner to the first toner chamber; By providing a partition plate between the second toner chamber and a toner feeding movable means that is moved by the toner remaining amount detection means on the bottom side, the toner in the first toner chamber can be sufficiently stirred and fed as necessary. The developer in the developer chamber is stirred and mixed uniformly throughout the developer chamber, and the developer is sufficiently charged, making it possible to obtain good image quality. It is possible to supply toner without toner remaining at the bottom.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an embodiment of a developing device according to the present invention;
3 and 4 are cross-sectional views of a developing device disclosed as prior art. 26...Developer, 27...Layer thickness regulating member, 28...Developer guide member, 29...
・Regulation board. Name of agent: Patent attorney Toshio Nakao and one other name
2 Figure

Claims (2)

[Claims] (1) Consists of a rotatable magnetic roll having multiple magnetic poles, and a non-magnetic sleeve that encloses the magnetic roll and is rotatable relative to the magnetic roll, with magnetic carrier and toner on the surface of the sleeve. a developing roller that holds and conveys a developer made of a mixture of the above, a layer pressure regulating member disposed opposite to the sleeve surface to regulate the layer thickness of the developer held and conveyed on the developing roller, and the developing roller a developer chamber for accommodating the developer conveyed by the developer chamber; a regulating member installed facing the sleeve surface to form the developer chamber; and a regulating member extending in the axial direction of the sleeve on the upstream side of the developer chamber. a guide plate forming a supply path for supplying toner to the developer chamber; a toner supply means for stirring the toner and supplying the toner into the toner supply passage; a first toner chamber having the toner supply means; a second toner chamber that supplies toner to the toner chamber; a partition plate provided between the first and second toner chambers; and a remaining amount of toner detection device that is movable by rotation of the toner supply means. and a toner feeding movable means configured to be located between the first and second toner chambers and on the bottom side of the toner chamber and to be moved by the remaining toner amount detecting means. A developing device characterized by: (2) The developing device according to claim 1, wherein the toner feeding movable means is made of at least a resin sheet material such as polyester or polyethylene.