JP2783497B2 - Corona charging characteristics measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a corona charging characteristic measuring apparatus for measuring a change over time in the band coulometric powder shaped body.

[0002]

2. Description of the Related Art Conventionally, when a test object is a powder,
The change in the amount of charge with time due to corona discharge
In this method, a corona discharge device for performing corona discharge on the test object and a charge amount measuring device for measuring a change over time of the charge amount were separately provided. As a result, artificial movement is inevitable when the charged test object is moved, and it is difficult to maintain a complete insulation state with the outside world. Measurement was difficult. In addition, since the relative positional relationship between the test object and the charge amount measuring device slightly changes with each measurement, there is also a problem in the reproducibility of the measurement results. In addition, since it is difficult to move from the corona discharge device to the charge amount measurement device within a short fixed time, it is difficult to measure a steep attenuation characteristic of the charge amount immediately after the corona discharge. Further, since the DUT is moved by a person, the above-described corona discharge device and the charge amount measurement device must be provided relatively close to each other, and the corona discharge by the corona discharge device causes noise in the charge amount measurement device. And this also hindered accurate measurement of the charge amount.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a corona charging characteristic measuring apparatus which can measure the decay characteristic of the charging amount immediately after corona discharge with high accuracy and high reproducibility.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention , a layered powder is charged by corona discharge, and the charge decay characteristic of the powder is measured. in corona charging amount measuring apparatus, the filling of the layered
Charging means for charging the powdery material by corona discharge,
Provided at a predetermined distance from the charging means,
A charge amount detection means for detecting a charge amount of the serial powdery material, said strip
Containing the charging means and the charging amount detecting means and being sealed
The casing forming the measurement system and the casing
An object to be measured for taking in and out the provided powdery body
Take-out port and the layered filled powder
From the outlet to the charging means, and from the charging means
Conveying means for conveying to said charge amount detecting means, the transport
Means for detecting the transport position of the powdered material transported by the means
Therefore, the arrangement position of the outlet and the arrangement of the charging means
Installation position and the installation position of the charge amount measuring means.
And powdery position detecting means provided Les, the powdery body position
The detection means causes the powder to be disposed at the position of the take-out port.
In the position where the charging means is located
And charging control means for setting the charging means to be in an operable state only when the charging is detected .

[0005]

The corona charging characteristic measuring device of the present invention operates as follows.

[0006] charging means, the surface of the filling layer is charged by corona discharge by filling a DUT pulverulent body in layers.

The charge amount detecting means detects the charge amount of the charged DUT.

The conveying means conveys the device under test, to which the electric charge is applied by the charging means, from the charging means to the charged amount detecting means with high accuracy within a fixed time. Therefore, the accuracy and reproducibility of the measurement are guaranteed. The transport position of the device under test is detected by the transport position detecting device, but the charging device is operable only when the device under test is located at the charging device. The above operation is controlled by the charging control means, but is for safety measures against a high voltage for performing corona discharge.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a corona charging characteristic measuring apparatus according to the present invention. FIG. 1 shows an overall configuration diagram of the apparatus. This device can be broadly classified into three elements: a measuring element for charging the DUT by corona discharge and detecting the charged amount, a transport element for transporting the DUT, and a control element for controlling the device. .

Inside the casing 2A located on the lower left side of the corona charging characteristic measuring device 1, a high voltage adjusting sliderac 10, which constitutes a part of the measuring element, is provided.
Neon transformers 11 are disposed inside a casing 2B located on the upper left side of the device 1. The high voltage adjusting sliderac 10 is for adjusting a corona discharge voltage generated in a corona discharge electrode described later with high accuracy. The neon transformer 11 is for boosting the output voltage adjusted by the high-voltage adjusting slider pack 10 to a high voltage of several kV by the transformation ratio of the neon transformer 11, and applying the voltage to the corona discharge electrode.

Further, in this figure, a voltmeter 13 for displaying a high voltage is provided on the front surface of the casing 2B. Is to measure the voltage of The scale directly displays the secondary voltage in consideration of the transformer ratio of the neon transformer 11. That is, the voltage applied to the aforementioned corona discharge electrode is displayed.

On the upper side of the voltmeter 13 are lamps 14 and 1 for displaying a high voltage, which are turned on when a high voltage is generated.
5 are provided to take safety measures against electric shock and the like.

At a substantially central portion of the corona charging characteristic measuring device 1, a transfer mechanism 20 constituting a transfer element is provided. The transfer mechanism 20 includes a transfer table 24 on which a device under test 22 is mounted, and a transfer table 24. 24, and a driving motor 28 for driving the moving wire 26. The movement motor 28 is provided inside the casing 2A. Movement wires 26 are attached to both ends of the transfer table 24 in the movement direction, and the movement wires 26 form a closed loop via a drive motor 28.
Therefore, when the moving wire 26 is moved by the driving motor 28, the carrier 24 is moved to the moving wire 26.
Is moved in the left-right direction in the figure according to the movement of. In the upper right part of the transport mechanism 20, there is provided a take-out opening 3 which is opened and closed when the DUT 22 is placed on the carrier 24 or taken out from the carrier 24. In the present embodiment, the drive motor 28 is described assuming a stepping motor. However, an AC or DC servo motor can also be used.

On the upper surface of the transport mechanism 20, a corona discharge electrode 30 for charging the DUT 22 mounted on the transfer table 24 by corona discharge and a surface for detecting the charge of the charged DUT 22 are provided. The potential detector 31 is provided at a predetermined distance in the moving direction of the carrier 24. The separation is provided in order to prevent corona ions generated by the corona discharge electrode 30 from diffusing and adversely affecting the measurement of the surface potential detector 31.

A high voltage diode 32 for selecting the positive or negative of the voltage output from the secondary side of the neon transformer 11 is disposed on the upper outside of the casing where the corona discharge electrode 30 is provided. Which of 32 is connected to the corona discharge electrode 30 can be selected by a switch (not shown). Therefore, if the selection is made so that the left high-voltage diode 32A is connected to the corona discharge electrode 30, the DUT 22 can be positively charged, and conversely, the right high-voltage diode 32B can be connected to the corona discharge electrode 30. If the selection is made so as to be connected to 30, the device under test 22 can be negatively charged.

The corona charge decay characteristic of the DUT 22 can greatly enhance the knowledge obtained by measuring both the positive charge and the negative charge. Therefore, simple switching between positive charging and negative charging is indispensable.

The surface potential detector 31 indirectly measures the charge amount of the device under test 22 through a vibration electrode (not shown). Although the details of this measurement will be described later, generally, the change over time of the charge amount of the detection target 22 positioned below the surface potential detector 31 is continuously detected over a long period of time. By graphing the change over time, the charging characteristics of the DUT 22 are measured.

In order to accurately measure the surface potential, the size of the vibrating electrode needs to be at least 5 to 6 times larger than the size of the DUT 22. Therefore, the DUT 22 may have a diameter of about 3 cm, and a small amount of the DUT is sufficient for the corona charging characteristic measuring apparatus of the present invention.

When measuring the charge measurement, for example,
When the test object 22 is a powder, the capacitance C of the powder layer must be known in order to obtain the charge amount Q (Q
= CV), but generally it is often difficult to determine the capacitance C of the powder layer. However, if an accurate C is not required using a vibrating electrode, the test object 2
It is sufficiently possible to evaluate the chargeability of the powder from the surface potential V of No. 2 and, in addition, it is possible to obtain a result with little noise and good reproducibility.

A casing 2C constituting a control element is provided substantially at the lower right of the corona charging characteristic measuring device 1.
A control box 40 is provided in the casing. The control box 40 includes various control circuits and measurement circuits. A power switch 41 and a power lamp 4 for displaying an operation state of the power switch 41 are provided on a front surface of the control box 40.
2. A high voltage switch 43 for applying a voltage to the corona discharge electrode 30 and a display lamp 44 for displaying an operation state of the high voltage switch 43 are provided. Also,
An operation switch 45 operated to move the carrier 24 to the right in the figure, a display lamp 46 for displaying the operation state of the operation switch 45, an operation switch 47 operated to move the carrier 24 to the left in the figure, A display lamp 48 for displaying the operation state of the operation switch 47 is also provided.

FIG. 2 is a diagram showing details of the transport mechanism 20 also shown in FIG. The transfer table 24 is for placing and transporting the device under test 22, and is configured to be able to move on two rails 49 and 50 laid in parallel on the floor surface in the horizontal direction in the figure. Things. A wire 26 is attached to the transfer table 24 as shown in FIG.
4 is moved with the movement of the wire 26.

At the center of the transport mechanism 20, a corona discharge electrode 30 for charging the device under test 22 by corona discharge is provided. The surface potential detector 31 for measuring the charge amount of the device under test 22 is provided on the left side of the transport mechanism 20.

A take-out position detector 51 for detecting the original position of the transfer table 24 is provided on the right side of the transfer mechanism 20. From the pickup position detector 51, the transfer table 24 is moved to the position of the take-out port 3. At some point, that is, only at the original position, the position detection signal is output.
On the other hand, a corona discharge position detector 52 is provided on the left side of the corona discharge electrode 30. The corona discharge position detector 52 outputs a position detection signal when the carrier 24 is located directly below the corona discharge electrode 30. It is. That is, it is detected that the carrier 24 is located at the optimum position where an effective corona discharge can be given to the device under test 22.

Further, a charge amount measuring position detector 53 is provided on the left side of the surface potential detector 31, and the charge amount measuring position detector 53 is provided when the carrier 24 is located immediately below the surface potential detector 31. To output a position detection signal to the CPU. That is, it is detected that the transfer table 24 is located at the optimum position where the charge amount of the device under test 22 can be accurately detected. These position detectors, especially the position detector 5
Since the position of the DUT 22 can be detected with high accuracy by the devices 2 and 53, the present device can perform high-accuracy measurement with good reproducibility and safely.

These position detectors 51, 52, 53
Although the present embodiment has been described assuming a non-contact type, this type is not limited to this, and it is a matter of course that a contact type may be used.

FIG. 3 is a block diagram showing a control system of the apparatus of the present invention. Control elements are divided into a transport control section 59, a discharge control section 60, and a measurement control section 61. The transfer control section 59 includes a transfer control circuit 55 and the drive motor 28. The transfer control circuit 55 controls the rotation direction and the rotation speed of the drive motor 28 based on the transfer signal from the control box 40. This transport signal is a signal output when the operation switch 45 or the operation switch 47 is operated. The drive motor 28 drives the wire 26 according to the operation of these switches. Since the wire 26 is connected to the carrier 24, the carrier 24 is consequently moved.

The discharge control section 60 comprises a discharge control circuit 56 and a corona discharge electrode 30. The discharge control circuit 56 causes the corona discharge electrode 30 to output corona discharge when a corona discharge output signal is output from the control box 40. This corona discharge is performed by the high voltage switch 4
The operation of the high-voltage switch 43 is enabled only when the carrier 24 is located directly below the corona discharge electrode 30 in consideration of safety. That is, the outlet position detector 5
1 and the corona discharge is performed only when the position detection signal is not output from the charge amount measurement position detector 53 and the position detection signal is output from the corona discharge position detector 52. I have to. Therefore, the discharge control circuit 56 is prevented from being brought into a corona discharge state irrespective of the signal from the control box 40 depending on the position of the carrier 24, and erroneous operation due to human operation or the like is prevented. As a result, danger to the human body and damage to the device, especially the surface potential detector, etc. are prevented.

The charge amount detector 61 includes a charge amount detection circuit 57
, A recorder 58 and a surface potential detector 31. The charge amount detection circuit 57 starts the charge amount detection on condition that the position detection signal is output from the charge amount measurement position detector 53, and the recorder 58 records the detected charge amount in time series. . This record is stored in the outlet position detector 51.
And when the position detection signal is not output from the corona discharge position detector 52 and the charge amount measurement position detector 5
3, that is, when the transfer table 24 is at the position of the surface potential detector 31. Note that the charge amount detection circuit 57 detects the charge amount in a state where the corona discharge is completely stopped, and prevents noise due to corona discharge or the like to perform precise measurement.

The corona charging characteristic measuring apparatus of the present invention configured as described above operates as follows.
This operation will be described with reference to FIG.

First, as shown in FIG. 4A, when the device under test 22 is placed on the carrier 24 and the operator operates the operation switch 47 to the ON side, the carrier control circuit 55 operates the switch 47. The drive motor 28 is rotated in a predetermined direction in response to the transport signal output by the control unit. As a result, the moving wire 26 is driven, and the carrier 24 moves to the left.

The movement of the carrier 24 is started in this manner. When the carrier 24 is positioned directly below the corona discharge electrode 30 as shown in FIG. 4B, the operator operates the operation switch 47 to the OFF side. I do. By this operation, the transport signal is not input to the transport control circuit 55, so that the drive motor 28 is stopped.

In this state, when the operator operates the high voltage switch 43 to the ON side, the discharge control circuit 56 receives the corona discharge output signal output by the operation of the switch 43 and causes the corona discharge electrode 30 to perform corona discharge. . The DUT 22 is charged by the corona discharge. Next, when the operator operates the high voltage switch 43 to the OFF side after a predetermined time has elapsed, the corona discharge output signal is no longer input to the discharge control circuit 56 by this operation, so that the corona discharge is terminated. That is, the corona discharge is performed only when the high-voltage discharge switch 43 is operated to the ON side by the operator. Further, as a condition for performing the corona discharge, the transfer table 24 needs to be located directly below the corona discharge electrode 30 as described above. Specifically, as described above, the case where the position detection signal is not output from the outlet position detector 51 and the charge amount measurement position detector 53 and the corona discharge position detector 52
This is a case where the position detection signal is being output from the device. As described above, the position of the carrier 24 is detected based on the signals from the plurality of detectors, even if the corona discharge position detector 52 has failed. This is for sure detection, and is based on the so-called fail-safe concept.

After this operation is performed, as shown in FIG. 4C, when the operator again operates the operation switch 47 to the ON side, the transport control circuit 55 outputs a transport signal output by the operation of the switch 47. Receiving drive motor 28
Is rotated in a predetermined direction. As a result, the moving wire 26 is driven, and the carrier 24 moves further to the left.
In this way, the movement of the carrier 24 is started, and when the carrier 24 is located immediately below the surface potential detector 31 as shown in FIG.
Operate to the side. By this operation, the transport signal is not input to the transport control circuit 55, so that the drive motor 28 is stopped.

The charge amount detection circuit 57 outputs a position detection signal from the charge amount measurement position detector 53 from the time when it is detected that the carrier table 24 is located immediately below the surface potential detector 31. On the condition that the charging has been performed, the charge amount detection is started, and the recorder 58 records the detected charge amount in time series. This recording is performed when the position detection signal is not output from the outlet position detector 51 and the corona discharge position detector 52, and the position is detected by the charge amount measurement position detector 53, that is,
This is performed only when it is reliably detected that the carrier 24 is at the position of the surface potential detector 31. As described above, the detection of the position of the carrier 24 based on the signals from the plurality of detectors is based on the fail-safe concept.

After the above series of processing is completed, the operation switch 45 is turned on to move the carriage 24 to the right.
You just need to move it to the side.

As described above, in the corona charging characteristic measuring apparatus according to the present invention, all the functions are incorporated in one housing, and the movement of the DUT and the application of the electric charge thereto are arranged on the front of the apparatus. All operations are performed by operating the switch, and the high-voltage operation is enabled only when it is confirmed that the carrier is securely in the predetermined position. Therefore, it is possible to ensure sufficient safety for the operator. In addition, the safety and high measurement accuracy of each measuring device constituting the corona charging characteristic measuring device of the present invention are guaranteed.

The object to be measured can be charged either positively or negatively. The corona discharge electrode and the surface potential detector are provided at a predetermined distance from each other, and they can operate simultaneously. Therefore, it is possible to accurately measure the charging characteristics of the object to be measured (the time-dependent change in the amount of charge and the attenuation characteristics) without being affected by disturbance due to noise or the like.

As described in the above embodiment,
The present invention relates to a method for measuring the time-dependent change in the charge amount of a powdery material as a test object.
It is suitable for measuring conversion.

Since the corona charging characteristic measuring apparatus of the present invention can be kept in a closed state during the measurement, the corona discharge environment can be changed by introducing nitrogen gas or dry air into the inside. Can be measured, and a great deal of knowledge about the corona charging characteristics of the test object can be obtained.

[0040]

As described above, in the present invention, the test object is charged by the charging means, and the test object charged by the charging means is transferred from the charging means to the charge amount detecting means for a certain period of time. The charge characteristics of the DUT are measured only when the position of the DUT is detected by the transfer position detection means, so that the charge amount decay characteristics immediately after the corona discharge. Can be measured with high accuracy without disturbance such as noise, and the operation is controlled by the charge control means, so that the charge amount can be safely measured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a corona charging characteristic measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed view of a transport mechanism 20.

FIG. 3 is a control block diagram of the device of the present invention.

4 (a) is an explanatory view of a transfer process at a take-out position of the transfer table 24, and FIG. 4 (b) is an explanatory view of a transfer process at a corona discharge electrode position of the transfer table 24. , FIG.
(C) is an explanatory view of a transfer process at the position of the surface potential detector on the transfer table 24.

[Explanation of symbols]

10: High voltage adjustment slider, 11: Neon transformer, 22: DUT,
24 ... Transfer stand, 26 ... Wire,
28: drive motor, 30: corona discharge electrode,
31: surface potential detector, 32: high-voltage diode, 51: outlet position detector, 52: corona discharge position detector, 53:
Charge amount measuring position detector, 58 ... recorder.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 27/60 G01R 29/24

Claims (1)

(57) [Claims] We claim: 1. The by powdery body filled in layers is charged by corona discharge, the corona charge measuring device for measuring the attenuation characteristics of the charge amount of the powdery material, has been powdered material charged into the layered Charging means for charging the toner by corona discharge, and a charging means provided at a predetermined distance from the charging means,
A charge amount detecting means for detecting a charge amount of the powdery material , and a housing for accommodating the charging means and the charge amount detecting means;
The casing forming the measured measurement system and the powdery substance provided in the casing.
Object to be measured, and the layered filled powdery material is taken out of the hole through the port.
Detection of the charge amount up to and from the charging unit
Conveying means for conveying to the means, and the conveying position of the powdery material conveyed by the conveying means
In order to detect the location of the outlet, the charging
Location of the means and location of the charge amount measuring means
And powdery position detecting means provided on each of the powdery material by the powder-like position detecting means said take-up
Not at the location of the outlet and at the location of the charging means
And a charging control means for setting the charging means to an operable state only when it is detected that the corona charging characteristic is present.