JPH09304342A - Toner density and electrification quantity measuring device in binary system developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously measure simply and highly precisely the toner density and electrification quantity by providing an air vent in such a state as to form a circumferential circulating flow in a unit cell. SOLUTION: After a developer storage space 5 of a unit cell 1 is filled with a developer and the upper lid 3 is closed, it is suckled from the bottom of a mesh 4. An air vent 15 in the upper lid 3 is so formed that a circumferential circulating flow is formed in the storage space 5 by this suction from the mech. The developer is thus sufficiently stirred by an air flow 17, so that a carrier 10 and a toner 11 in the developer are separated. The separated toner 11 is made to ride on the air flow 17 and discharged to the outside of the unit cell 1 through the mesh 4, so that the carrier 10 and the toner 11 and effectively separated. This constitution can simultaneously measure the toner density and the electrification quantity in a short time with a single suction operation and can precisely measure it with a simple means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring toner concentration and charge amount in a two-component developer, and more specifically, it has a simple structure and can simultaneously measure the toner concentration and charge amount. In addition, the present invention relates to a device that can be performed with high precision and simple operation.

[0002]

2. Description of the Related Art In the fields of electrophotographic copying and facsimile, a two-component developer, that is, a mixture of a magnetic carrier and an electrophotographic toner is widely used for visualizing an electrostatic latent image. There is.

In the magnetic brush development method using a two-component developer, charging is performed by friction between the magnetic carrier and the electrophotographic toner, and the charged developer forms an electrostatic latent image in the form of a magnetic brush. The toner is attracted to the electrostatic latent image by rubbing against the photoconductor or the like that it has, while the carrier remains on the developing roller provided with the magnet, and the developing operation is performed. The toner density and charge amount in a two-component developer have a significant effect on the density, image quality, fog, etc. of the image formed. Therefore, it is important to perform the measurement accurately and with simple operation. It is a very important issue in the field.

Conventionally, the toner charge amount has been measured by (1-1, blow-off method): a method in which toner is separated from a developer by gas pressure and the residual charge is measured, (1-2, developing current method): A method of calculating the charge amount of toner particles by measuring the movement of charges due to development as a current, (1-3, electric field transfer method): a method of measuring the toner transfer speed in an electric field and calculating the charge amount of toner particles , (1-4, surface potential method): A method of measuring the surface potential of the developed toner and calculating the charge amount of the toner particles is known.

Further, as a method of measuring the toner concentration, (2-1, carbon analyzer method): a method of measuring the amount of carbon dioxide generated from the developer at high temperature and calculating the amount of toner from the amount of carbon, (2 -2, cleaning method): A method of cleaning and removing only the toner in the developer and calculating the toner concentration from the weight difference is adopted.

[0006]

However, of the toner charge amount measuring methods, the blow-off method 1-1 has a problem that the carrier is destroyed by the gas pressure and the electric charge generated at this time is also measured. There is also the inconvenience that the toner density needs to be known. Further, in the developing current method 1-2, since the current is weak, there is a disadvantage that the measurement is unstable due to the influence of noise and the like. Furthermore, the above 1-
The electric field transfer method of No. 3 has a problem that it is difficult to separate and separate the toner particles one by one, and the apparatus is very complicated and large. Furthermore, in the surface potential method of 1-4,
There is a problem that it is difficult to obtain accuracy in measuring the layer thickness and distance of the developed toner.

Also, in the method of measuring the toner density,
In the 2-1 carbon analyzer method, a preliminary test is required for a developer with a known concentration in order to create a conversion formula, the spent toner adhering to the carrier surface is also measured, the device becomes very large, and it is consumed. There is a drawback that the product cost and the measurement cost are also high. Further, in the cleaning method 2-2, there is a problem that the measurement takes a lot of trouble and time, and the measurement accuracy is not high.

Therefore, the object of the present invention is to solve the above-mentioned drawbacks of the conventional method, to enable simultaneous measurement of the toner concentration and the charge amount, and also to enable simple and highly accurate measurement with a simple structure. Another object of the present invention is to provide a measuring device for toner concentration and charge amount.

[0009]

According to the present invention, a two-component developer is filled in a unit cell having a mesh at a lower portion and a ventilation hole at an upper portion or a side wall, and suction is performed through the mesh so that the unit cell is filled with the two-component developer. A toner concentration and charge amount measuring device that generates an air flow and discharges the separated toner to the outside of the unit cell through a mesh, and calculates the toner concentration from the weight difference before and after discharge and the toner charge amount from the residual charge after discharge. The vent holes are provided so as to form a circumferential swirl flow in the unit cell by suction through a mesh, and the swirl flow agitates and separates the toner while stirring the developer. An apparatus for measuring toner concentration and charge amount is provided.

According to the present invention, the toner concentration and the amount of charge are composed of a measuring unit cell having a two-component developer accommodating portion inside and a mesh at the bottom, and a housing accommodating and holding the unit cell. In the measurement unit, the housing includes the unit cell accommodating chamber and a suction chamber located below the accommodating chamber and communicating with the accommodating chamber, and an electrode is provided in a lower portion of the unit cell accommodating chamber. A ring-shaped unit cell support that doubles as a unit is provided so as to be electrically insulated from the housing wall, and the unit cell holds the mesh from the suction chamber while being held on the unit cell support. A vent is provided in the unit cell so that a swirl flow in the circumferential direction can be formed by suction, and the swirl flow causes the toner in the developer in the unit cell to flow. Toner density and charge amount measurement unit, characterized in that is discharged to the outside of the unit cell through the mesh is provided.

In the measuring device or the measuring unit of the present invention, the unit cell and the support have a work function difference of 0.6.
It is desirable that they are formed of a metal material of 0 eV or less, and most preferably the same metal material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In FIG. 1 for explaining the measuring principle of the present invention, a unit cell 1 is roughly composed of a cylindrical side wall 2, an upper lid 3 and a mesh 4. As is clear from FIG. 1, a flange 9 projecting outward is formed at the lower end of the cylindrical side wall 2.
Using this flange 9, the mesh 6 can be
Has been fixed. A substantially straight developer accommodating space 5 is formed in the cylindrical side wall 2, and the lower end of the developer accommodating space 5 is closed by the mesh 4. Further, the upper lid 3 is provided on the upper end of the cylindrical side wall 2 so as to be openable and closable, so that the developer can be taken in and out of the developer accommodating space 5. The developer is a mixture of the carrier 10 and the toner 11, and the mesh opening of the mesh 4 has such a size that the carrier 10 cannot pass through but the toner 11 can pass through. A grip portion (ring) 7 is provided on the outer periphery of the upper portion of the cylindrical side wall 2 in order to facilitate carrying of the unit cell 1. In the upper lid 3, so that an air flow is formed in the unit cell 1 by suction from below the mesh 4 described later,
The ventilation hole 15 is provided, and the ventilation hole 15 is provided with a mesh 16 for preventing powder scattering. The unit cell 1 is formed of a conductive material, particularly metal, so that the charge amount can be measured, and the meshes 4 and 16 are formed of the same material.

After the developer accommodating space 5 of the unit cell 1 is filled with the developer and the upper lid 3 is closed, suction is performed from below the mesh 4. In the present invention, the vent hole 15 of the upper lid 3
Is provided so that a circumferential swirling flow is formed in the developer accommodating space 5 by suction from below the mesh 4.
That is, the air flow 17 flowing into the developer accommodating space 5 becomes a downward vortex and passes through the lower mesh 4 while swirling in the circumferential direction along the wall of the cylindrical side wall 2. Therefore,
The developer filled in the developer accommodating space 5 is sufficiently agitated by such a vortex 17, and the carrier 10 and the toner 11 in the developer are separated, and the separated toner 11 is converted into the air flow 17. It is placed and discharged through the mesh 4 to the outside of the unit cell 1. By continuing this operation for a certain period of time, the carrier 10 and the toner 11 are effectively separated. That is, since such a swirling flow (vortex flow) is formed, the developer or toner existing in the vicinity of the container wall of the side wall 2 or adhering to the container wall can be effectively stirred and separated. This enables highly accurate measurement.

The charge of the carrier 10 is generated (residual) in the unit cell 1 in accordance with the separation and discharge of the toner, and the residual charge has the same absolute value as the charge of the toner. Therefore, the following formula (1): The toner charge amount (μc / g) is measured by.

Further, when the weight difference at this time is measured, the following formula (2): The toner density [%] is measured from.

The absorbed toner weight [g] is represented by the following formula (3): absorbed toner weight [g] = added developer weight [g] -residual developer weight [g] (3) .

In the present invention, the carrier of the developer and the toner are separated by utilizing the swirl flow (vortex flow) caused by the intake air of the unit cell. In order to effectively form such swirl flow. It is preferable to form the vent hole 15 as shown in FIGS. FIG. 2 is a plan cross-sectional view of the upper lid 3, and FIG. 3 is a side cross-sectional view showing the vent 15 of FIG. 2 in an enlarged manner.

That is, as shown in FIG. 2, a plurality of vent holes 1
5 is preferably formed in an axially symmetrical and spiral shape. By arranging the plurality of vent holes 15 axially symmetrically, particularly on the same circumferential line, the air flow can be introduced without forming a dead space in the developer accommodating space 5, and the spiral shape can be obtained. This makes it possible to form a swirl flow without stagnation. In addition, in FIG.
Is shown as two, but the number is arbitrary as long as a swirling flow is formed in a sufficient amount to stir the developer and separate the toner 11. Generally, the sum S1 of the opening areas of the vent holes 15 is calculated as the bottom area S2 of the developer accommodating space 5.
It is preferable to set the number and size of the vent holes 15 so as to be 6.3 to 14.1% with respect to the (effective area of the mesh 4). If the opening area of the vent hole 15 becomes unnecessarily large, a sufficient linear velocity for forming a swirl flow cannot be imparted to the air flow passing through the vent hole 15, and eventually a circumferential swirl flow is effectively formed. However, it tends to be difficult to uniformly and sufficiently agitate the developer and separate the toner. If the amount is too small, the gas flow rate flowing into the unit cell is too small, and the agitation of the developer and the toner are also caused. Separation tends to be inadequate. Also in FIG. 2, the cylindrical side wall 2
The inner diameter (D, corresponding to the effective inner diameter of the mesh 4) and the distance (d) between the vent hole 15 and the cylindrical side wall 2 have a d / D of 0.2.
It is preferably in the range of 5 or less. This is because if the vent hole 15 is formed at a position far away from the cylindrical side wall 2, the air flow from the vent hole 15 tends to become a laminar flow in the axial direction.

Further, as shown in FIG. 3, it is preferable to form a blade 18 inside the vent hole 15 (on the side of the developer accommodating space 5) whose tip extends substantially parallel to the inner surface of the upper lid 3. Is. This is because the blades 18 serve as guides to form a swirling flow in the circumferential direction. Of course, the blades 18 are directed in the same direction so that the airflows flowing in from the respective vents 15 form swirl flows in the same direction. Such a blade 18 can be easily formed by cutting and pressing the portion of the upper lid 3 where the vent hole 15 is formed, leaving the base portion of the blade 18.

Further, in the present invention, in order to effectively form the swirl flow described above, the interval (height H) between the vent hole 15 and the mesh 4 and the inner diameter of the bottom portion of the developer accommodating space 5 (effectiveness of the mesh 4 are effective). Inner diameter) D ratio (H / D) is 0.5 to 1.25
It is preferable that it is in the range of. If this value is larger than the above range, the air flow tends to become a laminar flow in the vertical direction, and not only a sufficient swirling flow is not formed, but also the developer is attracted to the mesh 4 and the stirring effect tends to deteriorate. There is. On the other hand, if it is smaller than the above range, a sufficient linear velocity is not given to the air flow and the swirl flow is apt to be insufficiently formed. Further, in FIG. 1, the cylindrical side wall 2 is shown as a substantially straight shape, but it is a taper shape (that is, a funnel shape) in which it is tapered as it goes downward.
The effect of stirring and separation due to the swirling flow (vortex flow) can be enhanced by setting the above.

In the above example, the ventilation hole 15 for forming the swirling flow is formed in the upper lid 3, but the ventilation hole 15 may be provided in the cylindrical side wall 2. In this case, it is preferable to provide the vent hole 15 as high as possible so that a dead space is not formed. For example, in FIG. 1, the vent hole 15 is provided at a portion above the grip portion 7 of the cylindrical side wall 2. Is preferably provided. Further, even when the vent hole 15 is provided in the cylindrical side wall 2, the vent hole 15
It is preferable to dispose a plurality of the above in axisymmetric manner in order to form a swirling flow in the circumferential direction, and it is further preferable to provide the ventilation holes 15 with the blades 18 as shown in FIG.
An example in which such a blade 18 is provided is shown in FIG. FIG.
FIG. 3 is an enlarged side sectional view showing a vent hole 15 provided in the cylindrical side wall 2, and as shown in this figure, the vent hole 15 is
A blade 18 is provided on the developer storage space 5 side. That is, the blade 18 functions as a guide for the air flow, as in the example of FIG. 3, and is directed inward so that a swirling flow in the circumferential direction is formed.

In the measuring device of the present invention, as described above, by using the unit cell provided with the vent capable of forming the swirling flow in the circumferential direction, the toner concentration T / D and the charge amount can be obtained by a single operation. Simultaneous measurement with Q / M is possible, and there is an advantage that both the concentration and the charge amount can be accurately measured from a developer whose toner concentration and composition are unknown.

FIG. 5 shows the toner concentration of a two-component developer having a known toner concentration (T / D) by the known carbon analyzer method (▲) and the suction method (□) using the measuring device of the present invention. The result of the measurement (for details, see the example described later) is shown. According to FIG. 5, the toner density value according to the sample density is obtained, which shows that the accuracy is high. It can be seen that the present invention is practically superior in terms of simplicity of the device and operation.

FIG. 6 shows the charge amount of a two-component developer having a known toner concentration (T / D) measured by the known blow-off method (▲) and the suction method (□) using the measuring apparatus of the present invention. The result (see the example described later for details) is shown. FIG.
Shows that the change in the charge amount with respect to the change in the toner concentration shows a completely opposite tendency between the blow-off method and the method using the measuring apparatus of the present invention, but the decrease in the toner concentration indicates the increase in the toner charge amount. From the viewpoint, it is considered that the present invention shows the correct tendency.

The blow-off method and the method using the measuring apparatus of the present invention are in agreement in that an air flow is used for separating the toner, but in the blow-off method, the gas pressure used is considerably high and carrier destruction occurs. Have been confirmed. It is considered that, due to the carrier destruction, positive or negative extra charge is generated depending on the agent. On the other hand, in the present invention, the suction is used, and the toner is completely separated by the generation of the circumferential swirling flow (vortex flow) without applying the gas pressure that causes the carrier destruction like the blow-off method. It is a thing. In fact, it has been confirmed by electron microscope observation that no carrier destruction has occurred.

In the measuring apparatus of the present invention, a hollow unit cell support is provided above the suction chamber in an airtight and electrically insulated state, and the unit cell is detachably supported on this support. With this configuration, not only the operation of charging and removing the developer into and from the unit cell can be easily performed, but also the weight of each unit cell can be measured, and the suction operation and the measurement of electric charge can be performed simply by mounting the unit cell on the support base. Is also possible.

By forming the unit cell and the support base from a metal material having a work function difference of 0.60 eV or less, in particular, the same metal material, it is possible to accurately measure the charge amount.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 7 showing an example of the overall arrangement of a measuring device of the present invention, this device comprises a measuring unit (device main body) 20, a main body control section 21, a suction pump 22,
It is composed of a charge meter 23 and a balance 24.

In FIG. 8 showing the detailed structure of the measuring unit 20, a base 30 made of, for example, stainless steel (SUS) is provided below the unit 20, and the base 30 is also made of stainless steel. A housing (shield case) 31 is provided. Inside the housing 31, the suction chamber 3 opened at the top
2 is provided, and the suction chamber 32 is connected to the above-described suction pump 22 via a hose 33. Further, an atmospheric pressure sensor 34 is arranged in the suction chamber 32, and a detection signal of the atmospheric pressure sensor 34 is supplied to the main body control section 21 by the cable 35. A unit cell accommodating chamber 36 is provided above the suction chamber 32, and a unit cell support 37 that also serves as an electrode is provided at the boundary between the accommodating chamber 36 and the suction chamber 32. The support base 37 is also made of stainless steel, and is fixed to the housing 31 by an embedded bolt 38 made of an electrically insulating material (resin). Further, a ring-shaped electric insulating material (silicone rubber) 39 is fitted between the support base 37 and the inner wall surface of the housing 31, and the support base 3
7 is provided in the unit 20 in an airtight state and in an electrically insulated state. The support base 37 is provided with the charge meter 23 described above via the internal wiring 40, the connector 41 and the cable 42.
It is connected to the. A lid 44 is provided on the upper portion of the unit cell storage chamber 36 via a hinge 43 so as to be openable and closable,
The lid 44 is provided with a vent 46 having a dust shield (400 mesh) 45.

Returning to FIG. 7, the operation panel section of the main body control section 21 is provided with a power switch 50, a start button 51, a stop button 52, a suction force adjusting knob 53, a digital barometer 54 and a timer 55. .

Start button 51 and stop button 5
2 drives the suction pump 22 to start the measurement, and stops the suction pump 22 to end the measurement.
The timer 55 sets a measurement time and stops the pump 22 at the set measurement time.

The suction force adjusting knob 53 is used for the suction pump 22.
It is for controlling the power supplied to the TRIAC. On the other hand, the digital barometer 54 displays the atmospheric pressure detected by the atmospheric pressure sensor 34 (FIG. 8), and by rotating the suction force adjusting knob 53, the pressure inside the suction chamber 32 (FIG. 8) can be arbitrarily set. Can be set to the value of.

The suction pump 22 is for reducing the atmospheric pressure of the suction chamber 32 (FIG. 8) to a predetermined pressure and for collecting the toner particles discharged, and the degree of vacuum is 300 to 120.
A 0 mm water column having an air flow of 0.01 to 1.00 m ³ / min and a toner collecting paper pack is preferably used. The pump used in this embodiment is a toner cleaner, more specifically, CV-TN95 manufactured by Hitachi, Ltd.

The charge meter 23 is for measuring the charge of the residual carrier, that is, the charge of the toner through the support base electrode 37, and a charge meter having a measurement range of up to 20 μC is used. The charge meter used in this example is
Advantest Digital Electrometer TR865
2 and Coulomb Range Extender R12601 (only required when extending the measurement range).

The balance 24 measures the weight of the developer or the residual carrier together with the unit cell 1. Since the amount of the toner sucked is a very small amount of about 0.01 to 0.05 g, it is less than the decimal point. It has a precision of four digits or more. In the present example, a read-only 0.1 mg Aegara 320 electronic balance made by Shimadzu Corporation was used.

In measuring the toner concentration and the amount of charge, the measurement conditions are considerably different depending on the type of carrier, the type of toner and the combination of both, so it cannot be specified unconditionally, but as a standard condition, the suction pressure is -6kPa or-
A suitable range is 13 kPa, a suction time of 20 to 60 seconds, and a developer sample amount of 0.4 to 1.0 g. Further, it is appropriate that the area of the mesh portion is 3 to 20 cm ² and the volume of the developer accommodating portion is 6 to 70 cm ³ . Furthermore, mesh 4
An opening degree of 400 mesh (Tyler standard) is suitable. That is, if the degree of depressurization is too small or the time is too short, the separation of the toner and the carrier is incomplete and the toner concentration T
/ D tends to be low or the charge amount Q / M tends to fluctuate. Conversely, if the degree of decompression is too high or the time is too long, part of the carrier peels off and T / D becomes high. Q / M tends to fluctuate due to discharge or excessive charging in the cell. Of course, it is needless to say that for a developer containing a fragile carrier or a toner that is difficult to separate, the optimum range should be set by changing the degree and time of the pressure reduction. If the sample amount of the developer is larger than the above range, the toner scattering in the apparatus increases, whereas if it is smaller than the above range, the toner amount becomes minute and the accuracy is deteriorated, which is not preferable.

In this example, the measurement was performed according to the following procedure. 1. Weigh the unit cell weight. ... A [g] Put the sample in the unit cell. 3. Weigh the unit cell containing the sample. ... B [g] Set the unit cell in the device. 5. Release the charge meter hold and reset to zero. 6. Press the start button to start suction. 7. When stopped, hold the charge meter and read the value. ... C [μC] 8. Weigh the unit cell weight. ... D [g] 9. Clean the unit cell.

Calculation

As the unit cell, a 400 mesh stainless steel mesh is attached to a cylindrical side wall (made of stainless steel) having an inner diameter D (corresponding to the effective mesh inner diameter) and a height H of 30 mm as shown in FIG. However, in addition to this, various stainless steel top lids provided with two vents having different positions and sizes (the basic position and structure of the vents are as shown in FIGS. 2 and 3, and the vents are (Covered with stainless steel mesh) was used. The values of S1 / S2 (%) and d / D of the unit cell used are shown in Table 1. Table 1 shows the results of experiments in which the carrier and the toner were separated by suction with respect to these unit cells. The measurement conditions are suction pressure -9k.
Pa, suction time 30 seconds, sample developer amount 0.4-1 g. In Table 1, ◯ indicates that the toner and the carrier were completely separated, and x indicates that the unseparated toner remained on the carrier.

[0040]

[Table 1]

Further, instead of the stainless steel cylindrical side wall used above, a transparent acrylic resin cylindrical side wall of the same size is used, and each of the upper lids used above is attached to this, and the developer is attached. Without filling, suction was performed at a pressure of -9 kPa, smoke of incense stick was flown, and the air flow was observed. In the experiment of Table 1, the vortex was observed in the case of using the upper lid in which the complete separation of the toner and the carrier was confirmed, but the vortex was hardly observed in the case of not using it.

Also, using a developer for electrophotographic copying machine DC-2556 manufactured by Mita Kogyo Co., Ltd., toner and magnetic carrier are accurately weighed and ball-milled to obtain a two-component toner having a toner concentration of 2 to 5%. Prepare a system developer, S1 / S
2 = 5.8%, d / D = 0.125 A unit cell equipped with an upper lid was used to measure the toner concentration and the charge amount under the same measurement conditions as in the experiment of Table 1. For comparison, measurement of toner concentration by a known carbon analyzer method and measurement of toner charge amount by a blow-off method were also performed. The obtained results are shown in FIGS. 5 and 6.

[0043]

According to the measuring apparatus of the present invention, the advantage that the toner concentration and the charge amount can be simultaneously measured in a short time with a single suction operation can be obtained. Further, it is possible to obtain the advantages that the toner concentration and the charge amount can be measured with a simple means and with high accuracy, and the device cost and the running cost are low. Furthermore, since the conversion formula is not required, the toner density of the developer whose density, composition, etc. are completely unknown should be measured, and the density value is not affected by the spent toner. Furthermore, since the swirling flow (vortex flow) by suction is used, the toner separation can be effectively performed without destroying the carrier, so that the toner charge amount can be accurately measured.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining the measurement principle of the present invention, and is a cross-sectional view showing the structure of a unit cell.

2 is a plan sectional view of the upper lid shown in FIG. 1. FIG.

FIG. 3 is an enlarged side sectional view showing a vent hole shown in FIG.

FIG. 4 is a side cross-sectional view showing, in an enlarged manner, a ventilation hole provided in a cylindrical side wall of a unit cell.

FIG. 5 is a result of measuring a toner concentration of a two-component developer having a known toner concentration (T / D) by a known carbon analyzer method (▲) and a suction method (□) using the measuring device of the present invention. It is a graph which shows.

FIG. 6 is a graph showing a result of measuring a charge amount of a two-component developer having a known toner concentration (T / D) by a suction method using a known blow-off method and the measuring device of the present invention.

FIG. 7 is a layout view showing the entire measuring apparatus of the present invention.

FIG. 8 is a cross-sectional view showing details of a measuring unit used in the measuring apparatus of the present invention.

[Explanation of symbols]

1: Unit cell 2: Cylindrical side wall 3: Upper lid 4: Mesh 15: Vent 17: Airflow 18: Blade 20: Measuring unit 21: Main body control unit 22: Suction pump 23: Charge meter 24: Balance 30: Stand (Stainless Steel) 31: Housing 32: Suction Chamber 34: Atmospheric Pressure Sensor 36: Unit Cell Storage Chamber 37: Unit Cell Support

Claims (4)

[Claims] 1. A two-component developer is filled in a unit cell having a mesh in the lower part and a ventilation hole in the upper part or the side wall, and air is generated in the unit cell by sucking through the mesh, and the separated toner is meshed. The toner concentration and charge amount measuring device calculates the toner concentration from the weight difference before and after discharge and the toner charge amount from the residual charge after discharge. Is provided so as to form a circumferential swirl flow in the unit cell, and the toner is suctioned and separated while stirring the developer by the swirl flow, and the toner concentration and charge amount measuring device is characterized. . 2. The measuring device according to claim 1, wherein a plurality of the vents are provided in the lid of the unit cell in an axially symmetrical manner. 3. The measuring device according to claim 1, wherein a plurality of the vent holes are provided in the side wall portion of the unit cell in axial symmetry. 4. A toner concentration and charge amount measuring unit comprising a measuring unit cell having a two-component developer accommodating portion inside and a mesh at a lower portion, and a housing accommodating and holding the unit cell. The housing includes the unit cell accommodating chamber and a suction chamber located below the accommodating chamber and in communication with the accommodating chamber, and a ring-shaped unit also serving as an electrode is provided under the unit cell accommodating chamber. The cell support is provided so as to be electrically insulated from the housing wall, and the unit cell is held on the unit cell support by suction through the mesh from the suction chamber, Vents are provided inside so that a swirling flow in the circumferential direction can be formed, and the swirling flow causes the toner in the developer in the unit cell to pass through the mesh. Toner density and charge amount measurement unit, characterized in that is discharged out Nittoseru.