JPS58192037A - Developing device - Google Patents

Abstract

PURPOSE:To keep density of a developer constant at all times, by providing a stirring body having a magnet, in a replenishing vessel of a concentrated developer, driving the stirring body by giving a variation magnetic field from the outside, and stirring the developer. CONSTITUTION:A replenishing bottle 1 of a concentrated developer is set to a copying machine body, in its inverted attitude, a stirring magnet 9 formed by sticking a permanent magnet 9a to a rubber sheet 9b is placed in the inside, and an electromagnet 10 to which an AC power source 11a is connected is provided on the outside. When AC of prescribed frequency is supplied to the electromagnet 10, a variation magnetic field is generated, the magnet 9 executes attraction and repulsion, moves freely in the vessel, the replenished liquid is stirred and its density becomes constant. Subsequently, a solenoid 6 is operated by a signal of a density detector 7, a valve 3 is opened, and the replenished liquid having constant density is replenished to a vessel 8. Therefore, the density of the developer can be kept constant at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid developing device having a stirring means, and particularly to a liquid developing device for a wet type electrophotographic copying machine. 4 40f4ru.

Conventionally, in a wet-type electrophotographic copying machine, a developing device in which a concentrated developer bottle for replenishment is replaced in a two-way manner has been constructed as shown in FIG. In Figure 1,
A bottle l for replenishing concentrated developer is detachably set in the main body of the electrophotographic copying machine. The solenoid 6' is activated as appropriate by the signal sent from the #1 degree detector 7' which detects the developer concentration in the developer container 8', and the valve pusher and L lever 5' connected thereto are interlocked. . This valve push-up (f L
/ /(-5' is in contact with the tip of a rod 4 that operates the valve 3' provided in the center of the cap 2' of the replenishment bottle 1', and the tip of the valve push lever 5 is moved up and down. −
The valve 3' opens and closes according to the operation, and the concentrated developer is poured into the developer container 8.
The retracting liquid concentration was kept constant. On the other hand, toner particles may settle down over time in the developing solution.
In other words, the specific gravity of the material is adjusted to prevent separation of solute components such as solvent and toner as much as possible and to maintain a constant developer concentration.

Various improvements have been made by examining particle size, viscosity, etc.

However, in recent years, there has been an increasing demand for securing image density comparable to that of plain paper in various application papers such as postcard paper and peeler paper, and to meet this demand, there is a tendency for toner particle diameters to become larger.

However, in the case of a developer with a large toner particle size, toner particles and other solid components settle below the concentrated developer replenishment bottle 1' after the standing time has elapsed, despite the above-mentioned material improvements. However, since the concentration and viscosity of the developer becomes uneven, the amount of replenishment may not be sufficient or the concentration of the developer to be replenished may change, making it difficult to maintain a constant developer concentration, resulting in poor image quality. This caused the inconvenience of lowering the .

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a developing device that can constantly keep the concentration of the developer constant by uniformly stirring the concentrated developer using a simple device. shall be. The present invention is characterized in that the developing device maintains the developer concentration constant by appropriately replenishing the concentrated developer according to the developer concentration.
an agitator having a magnet installed in the replenishment container for the concentrated developer; and a driving means provided outside the replenishment container for driving the liquid agitator by applying a varying magnetic field to the agitator. This is a point to have.

Next, an embodiment of a liquid electrophotographic copying machine according to the present invention will be described with reference to the accompanying drawings. FIG. 2 is a schematic explanatory diagram showing an l'A-example of the developing device according to the present invention. In FIG. 2, reference numeral 1 denotes a cartridge-type replenishment bottle for concentrated developer, which is detachably set in an inverted position at a suitable position in the developing process of a wrinkle-type electrophotographic copying machine.

The replenishment bottle 1 has a slope sla formed by recessing one part of its side wall into the chamber MK.

A stirring magnet 9 is arranged inside this replenishment bottle l. This stirring magnet 9 is constructed by sticking rubber sheaths 9b having a slightly larger area than the two opposing faces of a permanent magnet 9&, which is actually a substantially rectangular parallelepiped.

Here, the rubber sheet 9b is attached so that the permanent magnet 9a is disposed approximately at the center thereof, so that the entire periphery thereof is approximately equally left over. Therefore, even if the stirring magnet 9 moves freely inside the replenishment bottle l, the permanent magnet 9a
does not come into direct contact with the inner surface of the replenishment bottle l, and the generation of contact noise is suppressed. In addition, the shape and number of rubber sheets 9b are determined according to the shape of the permanent magnet 9a so that the permanent magnet 9& does not come into direct contact with the inner surface of the replenishment bottle 1, and so that an appropriate stirring effect can be obtained. There are folds that must be pasted. Near the outside of this replenishment bottle l, there is an AC power supply
The electromagnet lO is connected to a control circuit 11 having 11&
is installed. In this example, the electromagnet 10 is placed at a corner portion near the side m1lk()O@1@, which is opposite to the side wall where the sloping portion 1a of the replenishment bottle 1 is formed, and its tip 101 are arranged close to each other. This arrangement is determined from the relationship with the slope l&, and when the replenishment bottle 1 is set in the reverse position, the stirring magnet 9 always slides down the slope @ 1 m and is automatically placed near the corner l. Designed for fishing. Therefore, depending on the position and shape of the slope 111ao, various arrangements of the electromagnets 1O are possible. In addition, when this chain @ part l- is formed, the balance between the size of the stirring magnet and the width of the narrow space B to be formed is considered so that the narrow space BK stirring magnet 9 created at the base does not enter. There is a need.

In the developing device according to the present invention constructed as described above, a roughly bowl-shaped camp 2 with a concave center portion is attached to the mouth portion 1cK of the replenishment bottle l in which the agitation device is disposed. A hemispherical valve 3 is provided in the center of the bowl base of the cap 2.

For this valve 3, a hemispherical hole that matches the outer shape of the valve 80 bored in the center of the bottom of the bowl serves as a valve hole, and when the valve 3 is fitted into this hole, the closed state of the valve 1 is obtained from K. . One end of a rod 4 is directly connected to the valve 3, and the tip of a valve push-up lever 5 connected to a solenoid 6 is in contact with the other end. A coil spring 4a is fitted onto the rod 4 and biases the valve 3 toward the closed position 11IK. Valve push lever 5
The solenoid 6 connected to the developer container 8 is connected to a concentration detector 7 that detects the concentration of the developer in the developer container 8 .

The operation of the developing device according to the present invention configured as described above will be explained next. AC by switch 8 [source 11
When & is turned on and an alternating current of a predetermined frequency is conducted to the electromagnet IO, the electromagnet 10 forms a fluctuating magnetic field. That is, the direction of the magnetic field formed in synchronization with the zero frequency changes, and in response to this, the magnetic polarity 4hN and S of the tip 10m of the electromagnet 10 are alternately repeated. Therefore, as described above, due to the effect of the inclined portion 1a, the stirring magnet 9, which is always located in the vicinity of the electromagnet 10 in the replenishment bottle l, has two reversible magnetic forces of attraction and repulsion. act alternately, so they move freely in the vicinity of the corner part. This stirring magnet 90
The concentrated developer in the replenishment bottle is stirred and the concentration is kept constant.

Next, the operation of appropriately replenishing the developer container 8 with the concentrated developer whose concentration is kept constant will be described. When the developer in the developer container 8 becomes less than the reference value, the concentration detector 7 detects this and sends a signal to the solenoid 6. The solenoid 6 receives the signal and operates, and the valve push lever 5 is activated.
4 in the L direction, and push up the rod 4 that contacts the tip against the elastic force of the coil spring 41 to open the valve 3.

When the valve 3 is bent, the concentrated visual liquid, which is stirred by the stirring magnet 9 in the replenishment bottle l and maintained at a constant concentration, is supplied and replenished into the visual image mixing container 8. When the concentrated developer is replenished and the developer concentration exceeds the standard value, this
・：From the concentration detector 7 that detected the internal solenoid 6
When the @ signal is sent to the solenoid 6, the valve push lever S1 is returned to its original position. When the valve push lever 50 is released from its original position, the rod 4 is pushed down by the elastic force of the fill spring 4a. The valve 3 is closed, and the supply of concentrated developer is stopped. Through the above-described operations, a concentrated developer solution having a constant concentration is appropriately replenished into the developer container, and the concentration of the developer solution is kept constant.

Next, another embodiment of the developing device according to the present invention will be described based on the schematic explanatory diagram of Noodles 3. In this example, instead of the stirring magnet of the above embodiment, one end is fixed to the bottle mouth IC of one replenishment bottle 1, and the other end is a permanent magnet, and the elastic member to which 1a is fixed is preferably a flexible member. The plate spring 9' is installed inside the replenishment bottle l, and the other configurations are roughly the same as those of the previous embodiment. This leaf spring 9' is attached with its central part forcibly bent into an arched shape. Therefore, due to the elasticity of the leaf spring 9', the unrestrained tip is close to the mouth 1eK of the side wall lb of the replenishment bottle l. Press the inner surface of the part. Permanent magnet 91a fixed to this unrestricted tip
A rubber sheet 9'b is attached to the surface of the replenishment bottle IC) $1, and this rubber sheet 9'b is attached to the inner surface of the
The configuration is such that e is in contact with each other. From this K, stirring plate spring 9'
The electromagnet 10 in this example is located at the position closest to the permanent magnet *'aK, and its tip ioa and the permanent magnet 9'a are in contact with the side wall 1b and the rubber seam) 9. 'b are disposed in such a manner that they face each other. Here, the permanent magnet 9'a is on the side of the bottle l*
1bKWIi It is possible to configure the initial setting position of the permanent magnet la in operation 1 to be separated from the side wall 1b by a required distance so as not to hit the side wall 1b. In this case, the rubber sheet 9 is omitted. Furthermore, instead of the leaf spring 9',
It is also possible to construct the stirring body by using an elastic member such as a coil spring, fixing one end of the elastic member inside the bottle, and fixing a permanent magnet to the other end.

The operation of the stirring device in the developing device of this example will be described next. The electromagnet 10 of this example is also conducted with alternating current of a predetermined frequency as in the first embodiment, and in synchronization with this frequency, the magnetic polarity of its tip 10m also changes alternately between N and St. Therefore, the changing magnetic force in this direction acts on the permanent magnet 9'aK fixed to the unrestricted end of the closely opposing stirring spring plate 9'', repeating attraction and repulsion.
Therefore, the stirring plate spring 9' vibrates within the replenishment bottle l in synchronization with the frequency, and the concentrated developer inside is stirred uniformly to ensure a constant concentration. This concentrated developer solution kept at a constant concentration is replenished into the developer container 8 by the same operation as in the embodiment described above, and the concentration of the developer solution is kept constant.

Next, another embodiment of the electromagnet 100 control circuit 11 will be described. The concentrated developer may be stirred for at least several tens of seconds after being left still. In the above embodiment, the switch 8 is appropriately opened and closed manually to obtain an efficient stirring effect, but by incorporating a timer circuit into the control circuit 11, an efficient automatic stirring action can be obtained.

! 4 (Todoroki) Figure shows 24V DC power supply and timer device I.
2 shows a timer circuit configured by combining C and solid state relay SSR. In the m4 (&) diagram, zD is a zener diode, D is a diode, T is a transistor, C is a capacitor, and 8 is a resistor, and the same father has different predetermined values depending on each condition. are doing. Solid state relay SSRti (4th Cb) As shown in FIG.

In the control circuit 11 configured as described above, when the DC power 11Dc of the timer circuit lib is turned on after setting the bottle for replenishing concentrated developer, the solid state relay SSR is immediately activated, the control circuit 11' is made conductive, and the electromagnet The IO operates to stir the concentrated retracting liquid. When the set time has elapsed, the capacitor C1 is charged and the timer IC is turned off, and the connected solid state relay SSR is also turned off, so the control circuit 11' is cut off and the electromagnet 10 is also turned off. A self-stirring effect can be obtained.

As described in detail above, according to the present invention, m
By providing a convenient stirring device, the concentrated developer can be uniformly stirred and maintained at a constant concentration while being supplied to the developing process. Therefore, the developer concentration in the developing device is kept constant, good developing effects are exhibited, and image quality on various application papers can be improved. Furthermore, since the agitation device of the developing device according to the present invention has a simple mechanism, there is no disadvantage in terms of cost.Furthermore, when a rubber sheet is attached to the surface of the agitation body, agitation noise is not generated. suppressed.

It should be noted that the present invention should not be limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention.

For example, as shown in FIG. 5(a), the replenishment bottle l
A stirring device 10' for stirring the stirring magnet 9 inside,
Rotating magnet) 101 and this rotating magnet) 10&
It consists of a blade $10'e that is pivotally attached to the rotating shaft 16b of the
The impeller 10'e is immersed in the developer 8a, and the liquid flow from the developer pump 12 rotates the impeller 10'e, which rotates the rotating magnet io'a coaxially provided. It is also possible to stir the concentrated developer by driving the stirring magnet 9. Also, in this case, No. S (
kt) As shown in the figure, a rod-shaped magnet 9' is used as the stirring body, and this is rotated in the same manner as the rotation of the external rotary magnet 10'a, so that the concentrated developer is stirred by K. Also, if an electromagnet is used as the drive means and a timer circuit is installed to operate the timer circuit intermittently, this timer circuit can be linked with other parts of the copying machine such as the fuser & etc. to effectively control this intermittent agitation effect. It is also possible to adopt a configuration that implements the following. If you change the frequency of the AC power supply that operates the electromagnet to 4CI3I, the magnitude of the stirring action and the amplitude of the interlocking vibration of the beating can be made 1i to 16 times. Therefore, if desired, a more efficient stirring action can be obtained by setting the container to a unique maximum width state, that is, a resonance state, which is determined by the substance to be stirred, such as the developer concentrate. Father, it is possible to use not only AC wires but also DC power sources.

However, in this case, it is necessary to have a structure in which the electromagnet is intermittently excited by a known method, and the stirring body cooperates with such intermittent excitation of the electromagnet to obtain the desired O#i-stirring action. For example, as in the configuration shown in Fig. g3, the stirring body may be always biased in a predetermined direction, and the stirring body may be moved against this biasing force by intermittent excitation.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing a developing device of a conventional wet-type electrophotographic copying machine. 2 is a schematic explanatory diagram showing an embodiment of the developing device according to the present invention in a wet type electrophotographic copy mK;
The figure is a schematic explanatory diagram showing another embodiment of the developing device according to the present invention in a wet-type electrophotographic copying machine, FIG. 4(a), @
4(b) is a circuit diagram showing one embodiment of a timer circuit provided in the control circuit of the agitation device of the developing device according to the present invention, and a circuit diagram showing a control circuit of the agitation device in which the timer circuit is provided. , FIG. 5(a), and FIG. 5(b) show still another 2ffl@it of a wet-type electrophotographic copying machine having a developing device according to the present invention.
FIG. (Explanation of symbols) 1', l: Replenishment bottle 9: Stirring magnet 9*
, 9a: Permanent magnet jb, eb: Rubber sheet 9: Leaf spring lO: [Magnet patent applicant Ricoh Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 (b) Figure 1 O) Figure 5 (b) )figure

Claims (1)

[Scope of Claims] 1. In a developing device in which a concentrated developer is replenished according to the concentration of the developer, and in particular, the concentration of the developer is kept constant,
A stirring body having a magnet is provided in a supply container containing the concentrated developer, and a driving means capable of applying a fluctuating magnetic field to the stirring body from outside the supply container is provided, and the stirring body described in item 1 is driven by the fluctuating magnetic field. and stirring the concentrated developer in the supply container. 2. The developing device according to No. 111 above, wherein the agitating body has an end fixed to an elastic member fixed to the supply container No. 1. 3. In the above item 1, the driving means is t#! AK!
1. A developing device characterized by having an electromagnet that can be connected. 4. The developing device according to item 1 above, wherein the power source is an AC power source that can adjust the frequency.