JPH08304500A - Charged voltage meter - Google Patents

Abstract

PURPOSE: To provide a charged voltage meter whereby a charged voltage of an object to be measured such as a human body is measured without grounding the meter, and an operator can continuously measure the charged voltage of the operator itself by continuously holding it CONSTITUTION: The title device comprises a first conductor 1 provided in opposition to an object to be measured such as a human body, a second conductor 2 roughly insulated with the first conductor 1, a parallel circuit 3 consisting of a resistor Rs and a capacitor Cs that connects the first conductor 1 with the second conductor 2, an integrating means 31 that integrates voltages Vs generated on the resistor Rs when the object is charged and a charged voltage grasping means 26 that grasps the voltage charged on the object to be measured in accordance with an output from the integrating means 31 and generates an alarm corresponding thereto. The second conductor 2 is disposed such that an electrostatic capacitance having a constant value is generated across the second conductor and an earth section such as the outer ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging potential measuring instrument, and more particularly to a surface potential measuring instrument suitable for measuring the charging potential of a human body.

[0002]

2. Description of the Related Art As a conventional charging potential measuring device, for example, a sensor portion made of a conductive material is arranged at a predetermined interval on a measuring object, and at this time, the sensor portion is arranged according to the charging potential of the measuring object. It is generally known that the generated potential is detected, and the charged potential of the measurement target is grasped from the detected potential.This kind of charged potential measuring instrument is used, for example, in a semiconductor product manufacturing line, etc. Used when measuring.

On the other hand, in the semiconductor product manufacturing line and the like, in general, the presence of a charged object often causes a trouble in manufacturing due to the static electricity. Therefore, the object is not limited to various objects, but an operator (human body). It is desired to also measure the charging potential of). In this case, a portable charging potential measuring device is desired which allows the worker to continuously measure the charging potential of the worker while moving or working while accommodating the measuring device in a clothing pocket or the like. ing.

However, in the conventional charging potential measuring instrument, it has been difficult to satisfy the above demands as described below.

That is, in the conventional charging potential measuring device, the potential generated in the sensor portion in accordance with the charging potential of the measuring object uses an amplifying circuit, a level detecting circuit, etc. as a potential relative to the ground portion provided in the measuring device. Will be detected. Therefore, in order to correctly measure the charged potential of the measurement target, it is necessary that the potential of the ground part of the measuring instrument is maintained at a substantially constant level as the reference potential part (earth part) of the external environment of the measuring instrument, Therefore, the ground part of the measuring instrument is
Normally, it is grounded to a suitable grounding part such as the earth, where potential fluctuations are less likely to occur, through a grounding wire.

However, in a conventional portable charge potential measuring instrument carried by a measurer, for example, a casing held by the measurer is formed of a conductive material, and the casing serves as a ground portion of the measuring instrument. , There is a case where the ground part is not grounded to the ground part via a wire, but this kind of thing can be regarded as being grounded to the ground via the measurer who holds the case which is the ground part. In this case, the measurer measures the charging potential of objects other than himself / herself.

However, in such a conventional charged potential measuring instrument, as described above, basically, the ground portion of the measuring instrument is grounded via the earth wire, so that the moving range of the measuring instrument is limited. Limited. Therefore, as described above, it is difficult to measure the electrification potential of an operator who moves or works at will, and in order to perform the measurement, the operator himself / herself is appropriately sent to the place where the measuring instrument is installed. I have to do it.

Further, in the conventional portable charging potential measuring device, an uncharged worker can measure the charging potentials of other workers, but if he tries to measure his own charging potential. , Since the operator grips the housing of the measuring instrument, the potential of the ground part of the measuring instrument becomes the same potential as the operator himself due to the transfer of electric charge between the operator and the measuring instrument. Will end up. As a result, the electric potential of the sensor portion with respect to the ground portion of the measuring instrument becomes 0 V, and the operator's own charging potential cannot be measured. In this case, for example, even if the operator carries the measuring instrument through an insulator, capacitive coupling is made between the operator and the measuring instrument, and the potential of the ground part of the measuring instrument is the charged potential of the operator. However, it is impossible to correctly measure the electrostatic potential of the worker himself. As long as the operator carries the measuring device, the potential of the ground portion of the measuring device is the same as that of the worker, and therefore the worker cannot carry the measuring device and measure the charging potential of the worker.

[0009]

SUMMARY OF THE INVENTION The present invention eliminates such inconvenience and enables the measurement of the charging potential of a measuring object such as a human body without the need for grounding the measuring instrument, and the measuring person can continuously measure the charging potential. Another object of the present invention is to provide a charging potential measuring instrument capable of continuously measuring its own charging potential while carrying a measuring instrument.

[0010]

In order to achieve such an object, the present invention provides a parallel circuit including a first conductor arranged to face an object for measuring a charging potential, and a resistor and a capacitor connected to the first conductor. And is provided so as to be substantially insulated from the object to be measured and the first conductor and connected to the first conductor via the parallel circuit, and is arranged at a position where a substantially constant capacitance is formed between the first conductor and the outside world during measurement. The second conductor, and the first conductor
When a conductor is arranged to face the measurement object, an integrating means for integrating a current flowing through the resistance of the parallel circuit or a voltage of the resistance, and an integral value obtained by the integrating means are proportional to the charging potential of the measurement object. A charging potential grasping means for grasping the charging potential of the measuring object by the integrated value as a quantity is provided.

The charging potential grasping means is provided with an alarming means for issuing an alarm when the integrated value of the integrating means indicating the charging potential of the measurement object exceeds a predetermined value.

Further, the present invention is characterized by further comprising reset means for periodically resetting the integrated value obtained when the integrated value obtained by the integrating means is below a predetermined value.

The object to be measured is a human body, the first conductor and the second conductor are fixed to each other through an insulator, and the parallel circuit, the integrating means and the charging potential grasping means are housed inside. A body is formed by including the first conductor and the second conductor in a part of the body, and the casing is provided in a storage portion for clothing, with the first conductor facing the human body and the second conductor separating from the human body. It is characterized in that it is formed so that it can be accommodated.

[0014]

The operation of the present invention will be described with reference to FIGS.

FIG. 1 shows a model of the basic configuration of the charging potential measuring instrument A of the present invention. 1 is the first conductor, 2 is the second conductor, 3 is the resistor Rs and the capacitor Cs. It is a parallel circuit consisting of. The first conductor 1 and the second conductor 2 are substantially insulated by interposing an appropriate insulator or the like therebetween, and are connected via the parallel circuit 3.

In the measurement of the charging potential, the first conductor 1 is arranged so as to face the object W to be measured, and the second conductor 2 is substantially insulated from the object W to be measured. It is arranged so that a substantially constant capacitance is formed between it and the constant potential portion). At this time, the electrical model of this measurement system is expressed as shown in FIG.

In FIG. 1, Rh is the resistance between the first conductor 1 and the measurement target W (when the measurement target W is, for example, a human body, resistance due to clothes), and Ch is the first conductor 1 and the measurement target W. , Cg is a capacitor indicating the capacitance between the second conductor 2 and the ground E, and Cc is a capacitor indicating the capacitance between the first and second conductors 1 and 2. , Rc are resistances due to an insulator or the like between the first and second conductors 1 and 2. In the following description, the resistance Rs of FIG.
, Rh, Rc and capacitors Cs, Ch, Cc, Cg
The reference numerals of (1) and (2) also indicate the resistance value and the capacitance value of those resistors and capacitors, if necessary.

In the model of FIG. 1, the resistance Rs and the capacitor Cs of the parallel circuit 3, the first and second conductors 1,
Regarding the resistance Rc and the capacitor Cc between the two, Rs << R
If Rs and Cs are set so that c, Cs >> Cc,
The resistor Rc and the capacitor Cc can be neglected, in which case the electrical equivalent circuit of the model of FIG. 1 is represented as shown in FIG. In FIG. 2, V0 is a charging potential of the measurement object W with respect to the ground E, and Vg is a potential of the second conductor 2 with respect to the ground E (voltage of the capacitor Cg).

In the measurement system represented by such an equivalent circuit, when the charging potential V0 of the object W to be measured is generated, the movement of the charge generated between the first conductor 1 and the second conductor 2 and the object W to be measured causes Electric charges are stored in the capacitor (electrostatic capacity) Cg formed between the second conductor 2 and the ground E, and in the final steady state, the potential Vg of the second conductor 2 matches the charging potential V0 of the measurement target W. Like

At this time, the circuit shown in FIG. 2 behaves as follows in the process of Vg = V0 as described above.

That is, first, the charging potential V of the object W to be measured is
Immediately after the occurrence of 0, the transfer of charges via the resistors Rh and Rs is unlikely to occur immediately, so that the capacitors Cs and
Charge transfer occurs due to electrostatic induction due to capacitive coupling of Ch and Cg. Therefore, in this case, the circuit of FIG. 2 eliminates the resistors Rh and Rs and simply replaces the capacitors Cs and Cs.
It is equivalent to a circuit in which h and Cg are connected in series to a power source having a charging potential V0.

At this time, the capacitors Cs, Ch
, Cg generated by the voltages Vs, Vh and Vg are expressed by the following equations (1), (2) and (3), respectively.

[0023]

[Equation 1]

Therefore, the amount of charge stored in each capacitor Cs, Ch, Cg (= Cs Vs, Ch Vh, Cg Vg)
Are equal. That is, immediately after the charging potential V0 is generated, the electric charges are stored in the capacitors Cs, Ch and Cg in equal amounts. At this time, each capacitor Cs, Ch
, Qg is the amount of charge stored in Cg in equal amounts,
Q0 is represented by the following equation (4).

[0025]

[Equation 2]

In this way, the capacitors Cs, Ch, Cg
After the electric charges are stored in, the movement of the electric charges through the resistors Rh and Rs (current flows through the resistors Rh and Rs) starts. When the current flows through the resistors Rh and Rs, the electric charges stored in the capacitors Cs and Ch are discharged through the resistors Rs and Rh, respectively, and finally the voltage Vs of the capacitors Cs and Ch, Vh becomes 0V. At this time, the voltage Vg of the capacitor Cg finally becomes the charging potential V0.
Therefore, the electric charge flows from the object W to be measured through the resistors Rh and Rs. The resistors Rh and Rs
The transfer of the electric charge through the capacitor finally results in the capacitors Cs and Ch.
When the voltages Vs and Vh of 0 become 0 V and the voltage Vg of the capacitor Cg matches the charging potential V0, the process ends.

At this time, as shown in FIG. 2, the discharge current of the capacitor Cs via the resistor Rs is Is, and the resistors Rh and Rs.
If the current flowing through the capacitor Cg through the capacitor is Ig and the amount of charge stored in the capacitor Cg is Qg, then Qg
Is given by the following equation (5) using the charge quantity Q0 stored in the capacitor Cg immediately after the generation of the charging potential V0.

[0028]

(Equation 3)

The total amount of charge flowing through the resistor Rs is obtained by integrating the momentary total current (= Is + Ig) of the resistor Rs.

[0030]

[Equation 4]

Since the integrated value of the first term on the right side of the above equation (6) is the integrated value of the discharge current Is of the capacitor Cs, the integrated value is stored in the capacitor Cs immediately after the charging potential V0 is generated. It is equal to the amount of charge Q0. Therefore, the equation (6) can be rewritten as the following equation (7).

[0032]

(Equation 5)

Therefore, since the right sides of the equations (5) and (7) are equal, the amount of charge Qg stored in the capacitor Cg is
Is equal to the total amount of charge flowing through the resistor Rs. Ie

[0034]

(Equation 6)

On the other hand, the final voltage Vg of the capacitor Cg
Qg = Cg V0 (8) Therefore, from the above formulas (7) 'and (8), the charging potential V0 of the measurement target W is expressed by the following formula (9). Required by.

[0036]

(Equation 7)

Here, Cg in the equation (9) is an electrostatic capacitance which is determined by the distance between the second conductor 2 and the ground E and the size of the second conductor 2, and is the capacitance between the second conductor 2 and the ground E. By arranging the second conductor 2 at a position where the distance between them becomes a constant distance, Cg becomes a constant, and its value can also be obtained. The integral term on the right side of the equation (9) represents the integral value of the total current flowing through the resistor Rs.

Therefore, the charging potential V0 of the object W to be measured is proportional to the integral value of the total current flowing through the resistor Rs, and the charging potential V0 can be grasped according to the equation (9) by the integral value.

Since the current flowing through the resistor Rs = Vs / Rs, the equation (9) can be rewritten as the following equation (10).

[0040]

(Equation 8)

Therefore, the charging potential V0 of the object W to be measured is also proportional to the integral value of the voltage Vs of the resistor Rs, and it is possible to grasp the charging potential V0 according to the equation (10) by the integral value.

This is the principle of measurement of the charging potential V0 of the object W to be measured according to the present invention. The integrating means in the constituent features of the present invention integrates the current (Is + Ig) flowing through the resistor Rs or the voltage Vs of the resistor Rs. To do. Then, the charging potential grasping means uses the integrated value obtained by the integrating means according to the equation (9) or (10) to measure the charging potential V of the measuring object W.
Figure out 0. Incidentally, if the charging potential V0 increases or decreases, the integrated value also increases or decreases so as to follow it, so that the charging potential V0 can be continuously measured and grasped.

In the charging potential measuring device of the present invention,
The charging potential V of the measurement target W is calculated using the equation (9) or (10).
It is possible to obtain and understand the value of 0 itself,
When using the charging potential measuring device of the present invention in a semiconductor manufacturing line or the like, it is actually possible to grasp whether or not the charging potential V0 exceeds a certain level rather than grasping the value itself of the charging potential V0. preferable. Therefore, by providing an alarm means for issuing an alarm when the integrated value of the integrating means exceeds a predetermined value, it is determined whether or not the charging potential V0 of the measuring object W exceeds a level corresponding to the predetermined value of the integrated value. It becomes possible to easily understand the situation, and it becomes possible to detect the situation in which an appropriate measure such as grounding of the object to be measured must be taken according to the alarm, which is preferable in practice.

Further, the integrating means can be composed of, for example, an integrating circuit using an operational amplifier, but in this case, the operational amplifier generally produces an offset voltage, and the offset voltage is also integrated. And
When the measurement target is charged, the output of the integrating means is the sum of the integrated value corresponding to the charging potential and the integrated value of the offset voltage. Therefore, when the measurement of the charging potential of the measurement target is continuously performed for a long time, the integrated value of the offset voltage becomes excessively large as compared with the integration value according to the charging potential of the measurement target to be grasped, The grasp of the charging potential becomes inaccurate. Therefore, when the integrated value obtained by the integrating means is equal to or less than a predetermined value, the integrated value of the integrating means is periodically reset by the resetting means.
By doing so, the integrated value of the offset voltage is always maintained at a sufficiently small level, and when the measurement target is charged in this state, the integration value obtained by the integration means is accurately the charged potential of the measurement target. According to.
In this case, in the case of the charging of the measurement object such that the integrated value obtained by the integrating means exceeds the predetermined value within the reset cycle of the resetting means, the resetting of the integrated value by the resetting means is not performed. Therefore, it is possible to continuously grasp the charging potential of the measurement target from the integrated value by the integrating means within a time range in which the integrated value of the offset voltage does not become excessive. Further, in the case of the charging of the measuring object such that the integrated value obtained by the integrating means is less than the predetermined value, the charging potential of the measuring object is grasped from the integrated value by the integrating means within the reset period of the reset means. It is possible.

When a person carries the charging potential measuring device of the present invention and grasps the charging potential of himself, the first conductor and the second conductor are fixed to each other via an insulator, and
A case for accommodating the parallel circuit, the integrating means, and the charging potential grasping means inside is formed by including the first conductor and the second conductor in a part thereof, and the case is further provided in the accommodating portion of the clothes. By forming the one conductor toward the human body and the second conductor toward the side away from the human body, the charging potential measuring instrument of the present invention is accommodated in a storage part such as a pocket of clothing. It becomes possible to continuously grasp the self-charged potential while carrying the mobile phone as described above. In this case, in FIG.
Capacitance Cg formed between the second conductor 2 and the ground E
Causes some variation due to the difference in the storage location of the measuring instrument A and the variation in the distance between the second conductor 2 and the ground E due to the difference in height of individuals, but the degree of the variation is generally ignored. As small as possible. Therefore, the capacitance Cg can be regarded as substantially constant.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 3 is an external perspective view of the charging potential measuring instrument of this embodiment, FIG. 4 is a block diagram showing a circuit configuration of a main part of the charging potential measuring instrument, and FIG. 5 is a diagram for explaining the operation of the charging potential measuring instrument. It is a diagram. In the following description, the same components as those shown in FIG. 1 are designated by the same reference numerals.

With reference to FIG. 3, the charging potential measuring instrument A of this embodiment uses a human body as the measuring object W shown in FIG. 1, and the measuring object person carries his or her own charging potential in a semiconductor manufacturing line or the like. Is for grasping whether or not there is no problem, and is provided with a thin rectangular box-shaped housing 4. The casing 4 includes rectangular plate-shaped conductor plates 5 and 6 that form the front surface and the back surface of the casing 4, and a rectangular frame-shaped insulator 7 that forms an outer peripheral side wall of the casing 4 and is made of, for example, an acrylic material. It is composed by. The conductor plates 5 and 6 are fixed to the insulator 7 in a posture parallel to each other and insulated from each other through the insulator 7. Then, the housing 4 is configured such that one of the conductor plates 5 and 6 faces the human body side of the measurement target person (not shown), and the other conductor plate 5 or 6 faces the side away from the human body. It can be stored in a storage part (not shown) such as a pocket of clothes. In this case, the conductor plates 5 and 6 compose the first conductor 1 and the second conductor 2 shown in FIG. 1 at the time of measurement, and the conductor plate 5 is directed toward the human body to form the casing 4
1 is stored in the storage portion of the clothes, the conductor plates 5 and 6 become the first conductor 1 and the second conductor 2 of FIG. 1, respectively, and the casing 4 is stored in the storage portion of the clothes with the conductor plate 6 facing the human body. In this case, the conductor plates 5 and 6 are opposite to the second ones in FIG.
It becomes the conductor 2 and the first conductor 1.

In the inside of the housing 4, a circuit component 8 including the parallel circuit 3 shown in FIG. 1 and the like, and an alarm piezoelectric buzzer 9 for issuing an alarm when the person to be measured is charged. A battery 10 that is a power source of the circuit configuration unit 8 is housed. Further, on the upper surface of the insulator 7 forming the outer peripheral side wall of the housing 4, a power switch 11, a power monitoring LED lamp 12 indicating the voltage state of the battery 10 during operation, and resetting of an integrator described later. A reset switch 13 for operating and four alarm LEs for issuing an alarm when the measurement subject is charged
D lamps 14 to 17 are provided.

Next, the structure of the circuit structure section 8 inside the housing 4 will be described in detail.

As shown in FIG. 4, the circuit component section 8 is roughly divided into the first conductor 1 (conductor plate 5 or 6) and the second conductor 2 (conductor plate 6 or 5). A parallel circuit 3 composed of a resistor Rs and a capacitor Cs, an amplifier circuit section 18 for amplifying the voltage Vs of the resistor Rs, an integrating circuit section 19 (integrating means) for integrating the voltage Vs amplified by the amplifier circuit section 18, and an integrating circuit. A reset circuit unit 20 (reset means) for resetting the output of the circuit unit 19, and an integrating circuit unit 19
Of the comparison circuit unit 21 for comparing the output of the comparison circuit with a predetermined level, and the alarm LE according to the output of the comparison circuit unit 21.
Display circuit unit 22 for displaying the D lamps 14 to 17
And a buzzer circuit section 23 for making the alarm piezoelectric buzzer 9 sound according to the output of the comparison circuit section 21, and the battery 1.
The power supply voltage monitoring circuit section 24 monitors the voltage (power supply voltage) VD of 0. In this case, each circuit section 18-24
Is configured with one of the conductor plates 5 and 6 as the ground level. In addition, the first conductor 1 and the second conductor 1 are provided on the input side of the amplifier circuit unit 18 in order to prevent excessive input when the amplifier circuit unit 18 is not operating.
A relay switch 25 for input protection is provided between the conductors 2 in parallel with the parallel circuit 3. The relay switch 25 is opened in conjunction with the ON operation of the power switch 11 (see FIG. 3), and the OF switch of the power switch 11 is turned off.
It closes in conjunction with F operation (first conductor 1 and second conductor 2
Short circuit).

Incidentally, in accordance with the structure of the present invention, the comparison circuit section 21, the display circuit section 22 and the buzzer circuit section 23 constitute a charging potential grasping means 26, and the display circuit section 22 and the buzzer circuit section 23 are formed. The alarm means 27 is configured to include the alarm LED lamps 14 to 17 and the alarm piezoelectric buzzer 9.

In the present embodiment, the parallel circuit 3
As for the time constant (= Cs Rs), the values of Cs and Rs are set so that the frequency characteristic of the amplifier circuit section 18 is, for example, 100 Hz or less, for example, about 0.1 second.

The amplifier circuit section 18 includes a three-stage amplifier 28.
It is composed of a, 28b and 28c. in this case,
The gain of the first-stage amplifier circuit 28a can be adjusted by adjusting the resistance value of the variable resistor 29 connected thereto.

The integration circuit section 19 is composed of an integrator 31 connected to the output side of the amplifier 28c through an analog switch 30. The integrator 31 is configured by connecting a resistor and a capacitor to an operational amplifier (not shown), and an analog switch 32 for resetting its output (setting the output level to 0) is connected. The analog switch 32 resets the output of the integrator 31 when it is turned on. Incidentally, the integrator 31
Integrates the voltage Vs of the resistor Rs of the parallel circuit 3 amplified by the amplification circuit unit 18 with a predetermined gain, and the output thereof is, as is clear from the equation (10),
Basically, it indicates the charge potential of the measurement subject (proportional to the charge potential). In this case, in the present embodiment, the gain of the amplification circuit unit 18 is set so that the output of the integrator 31 during charging of the measurement subject is, for example, about 1/1000 of the charging potential of the measurement subject. ing.

The comparison circuit section 21 is composed of four comparators 33 to 36 which compare the output level of the integrator 31 with a predetermined level. In this case, the comparator 33 compares the output level of the integrator 31 with the + side reference high level set to a relatively high level on the + side, and the output level of the integrator 31 exceeds the + side reference high level. At that time, an L level signal (hereinafter referred to as the + side main alarm signal) indicating that is output. Further, the comparator 34 compares the output level of the integrator 31 with the + side reference low level (<+ side reference high level) which is set to a relatively low level on the + side, and the output level of the integrator 31 is +. When the side reference low level is exceeded, an L level signal (hereinafter referred to as the + side preliminary alarm signal) indicating that is output. Similarly, the comparators 35 and 36 respectively set the output level of the integrator 31 to a predetermined −side reference high level and −side reference low level (these magnitudes are the + side reference high level and the + side reference low level, respectively). Equal to the size) and the integrator 3
When the output level of 1 exceeds the − side reference high level and the − side reference low level to the − side, an L level − side main alarm signal and a − side preliminary alarm signal indicating that are output.

In this embodiment, the + side reference low level and the − side reference low level are, for example, ± 0.08 V, the + side reference low level.
The side reference high level and the − side reference high level are, for example, ± 0.
5V, and these have a charging potential of the measurement subject of ± 80
This corresponds to V and ± 500V.

The reset circuit section 20 includes an oscillator 37 with a frequency divider for generating and outputting pulse signals of plural kinds of frequencies.
A one-shot pulse generator 38 that receives and outputs the output of the oscillator 37 and generates and outputs a one-shot pulse that is a reset command signal for the integrator 31, and the power switch 11
A power-on reset signal generator 39 that generates and outputs a reset command signal for the integrator 31 in conjunction with the ON operation of (see FIG. 3), and a battery when the reset switch 13 (see FIG. 3) is turned on. Receives the voltage VD of 10
In response to this, a reset signal generation circuit 40 that generates and outputs a reset command signal for the integrator 31, and a reset command signal from the one-shot pulse generator 38, the power-on reset signal generator 39, and the reset signal generation circuit 40 are received. ON / OFF the analog switches 30 and 32.
It is composed of an analog switch switching circuit 41 for controlling.

In this case, the one-shot pulse generator 38
Receives a pulse signal of a predetermined cycle (for example, a 60-second cycle) from the oscillator 37 with a frequency divider, and periodically generates a reset command signal synchronized with the pulse signal. In addition, the analog switch switching circuit 41 basically includes the one-shot pulse generator 3
8. When a reset command signal is received from any of the power-on reset signal generator 39 and the reset signal generation circuit 40, the analog switch 30 is temporarily turned off (for 3 ms) to cut off the input to the integrator 31. The analog switch 32 is turned on and the integrator 31 is turned on.
Reset the output of. Note that the analog switch switching circuit 41 normally turns the analog switches 30 and 32 into the ON state and the OFF state, respectively, and when the reset prohibition command signal (H level signal) is given from the OR circuit described later, Regardless of the reset command signal of the one-shot pulse generator 38, the analog switch 3
0 and 32 are maintained in the ON state and the OFF state, respectively.

The display circuit section 22 includes the alarm LED.
LED drive circuits 42-45 for driving the lamps 14-17, respectively, and a duty 1 for generating a pulse for intermittently energizing the alarm LED lamps 14-17 by the LED drive circuits 42-45. / 4 pulse generation circuit 46. Each LED drive circuit 42,
43, 44 and 45 respectively include the comparators 33 and 3 respectively.
The outputs of 4, 36 and 35 are given through inverter circuits (level inverting circuits) 47, 48, 49 and 50. Each of the LED drive circuits 42, 43, 44, 45 has the level thereof inverted from each of the comparators 33, 34, 36, 35 by the respective inverter circuits 47, 48, 49, 50. , + Side preliminary warning signal, − side preliminary warning signal and − side main warning signal are given, the corresponding warning LED lamps 14, 15, 16 and 17 are energized and the warning LED lamps 14, 15, Turn on 16 and 17. In this case, the LED drive circuits 42 to 45 are
The alarm LED lamps 14, 15, 16, 1 are generated by the pulses given from the duty 1/4 pulse generation circuit 46.
7 is intermittently energized, but the energization period is sufficiently short, and each alarm LED lamp 1
Visually, 4, 15, 16, and 17 are adapted to continuously light up. By doing this, L for each alarm
The power consumption when the ED lamps 14, 15, 16, 17 are turned on is reduced, and the consumption of the battery 10 is suppressed.

The duty 1/4 pulse generation circuit 46
Generates a pulse for operating the LED drive circuits 42 to 45 as described above from a pulse signal of two types of cycles given from the oscillator 37 with a frequency divider.

Further, the outputs of the inverter circuits 48 and 49 for respectively inverting the levels (L level) of the + side preliminary alarm signal and the-side preliminary alarm signal of the comparators 34 and 36 are only the LED drive circuits 43 and 44. Not OR circuit 5
Similarly, the outputs of the inverter circuits 47 and 50 for inverting the levels (L level) of the + side main alarm signal and the − side main alarm signal of the comparators 33 and 35 are input to the OR circuit 52. Is entered. In this case, the OR circuit 5
The output of 1 is H when the comparators 34 and 36 output either the + side preliminary alarm signal or the-side preliminary alarm signal.
The level becomes L, and when neither the + side preliminary warning signal nor the-side preliminary warning signal is output, the level becomes L level. Similarly, the output of the OR circuit 52 is the comparators 33, 3
When 5 outputs either the + side main alarm signal or the-side main alarm signal, it becomes H level, and when neither the + side main alarm signal nor the-side main alarm signal is output, L level Becomes The output of the H level of the OR circuit 51 when either the + side preliminary alarm signal or the − side preliminary alarm signal is output from the comparators 34 and 36 is
It is given to the analog switch switching circuit 41 as a reset inhibit signal.

The buzzer circuit section 23 includes a piezoelectric buzzer drive circuit 53 for driving the alarm piezoelectric buzzer 9, and
An oscillator 54 for generating an oscillation signal necessary for operating the drive circuit 53 and applying the generated oscillation signal to the drive circuit 53. The piezoelectric buzzer drive circuit 53 is supplied with the outputs of the OR circuits 51 and 52, is supplied with a pulse having a period of, for example, 1 second from the oscillator 37 with a frequency divider, and is provided with an H level output from the OR circuits 51 and 52. When the warning is given, the warning piezoelectric buzzer 9 is driven to generate a warning sound. In this case, OR
When the H-level output is given from the circuit 51, that is, when the + side preliminary alarm signal or the − side preliminary alarm signal is output from the comparison circuit section 21, the piezoelectric buzzer drive circuit 53 causes the alarm piezoelectric buzzer. The alarm sound by 9 is intermittently sounded. Further, when the H level output is given from the OR circuit 52, that is, when the + side main alarm signal or the − side main alarm signal is output from the comparison circuit section 21, the piezoelectric buzzer drive circuit 53 outputs an alarm. The alarm buzzer 9 continuously sounds the alarm sound.

The piezoelectric buzzer drive circuit 53 is also provided with the output of the reset signal generation circuit 40 and the output of the LED drive circuit of the power supply voltage monitoring circuit section 24 described below, and the reset switch 13 is turned on. When the battery 10 is turned on or when the voltage VD of the battery 10 becomes lower than a predetermined voltage, the alarm piezoelectric buzzer 9 is driven to sound.

The power supply voltage monitoring circuit section 24 includes a comparator 55 for comparing the voltage VD of the battery 10 with a predetermined lower limit voltage.
And an LED drive circuit 56 for driving the LED lamp 12 for power supply monitoring. The LED drive circuit 56 is supplied with the output of the comparator 55, and the oscillator 37 with a frequency divider outputs, for example, 0. A pulse having a cycle of 25 seconds is applied, and the output of the duty 1/4 pulse generation circuit 46 is applied as in the case of the LED drive circuits 42 to 45. In this case, when the voltage VD of the battery 10 falls below a predetermined lower limit voltage, the comparator 55 outputs a signal indicating that to the LE level.
D drive circuit 56, at this time, the LED drive circuit 5
Reference numeral 6 blinks the LED lamp 12 for power supply monitoring in accordance with the pulse period given from the oscillator 37 with a frequency divider and the output of the duty 1/4 pulse generation circuit 46. And L
The ED drive circuit 56 is a power supply monitoring LED when the power switch 11 (see FIG. 3) is in an ON state in a normal state.
The lamp 12 is continuously turned on.

In the LED drive circuit 56, the voltage VD of the battery 10 falls below a predetermined lower limit voltage, and the power supply monitoring LED
When the lamp 12 is made to blink, a signal for causing the alarm piezoelectric buzzer 9 to generate an alarm sound is given to the piezoelectric buzzer drive circuit 53.

Next, the operation of the charging potential measuring instrument A of this embodiment will be described.

As described above, when the person to be measured (not shown) stores the charging potential measuring instrument A of this embodiment in the storage portion such as his own pocket and turns on the power switch 11, the circuit component portion is turned on. 8 is activated and the relay switch 25 is opened. At this time, the reset circuit unit 2
A reset command signal is given from the power-on reset signal generator 39 of 0 to the analog switch switching circuit 41, and the analog switch switching circuit 41 turns off the analog switch 30 and turns on the analog switch 32. The output of the container 31 is reset. Further, the reset command signal of the power-on reset signal generator 39 is given to the piezoelectric buzzer drive circuit 53 as a buzzer drive command signal, and the piezoelectric buzzer drive circuit 5
3 causes the piezoelectric buzzer 9 to ring temporarily. Further, the comparator 55 of the power supply voltage monitoring circuit section 24 compares the voltage VD of the battery 10 with a predetermined lower limit voltage, and at this time, the battery 10
Is not consumed so much and VD> lower limit voltage, L
The LED lamp 12 for power supply monitoring is controlled by the ED drive circuit 56.
Is turned on.

After such an initial operation is performed, the charging potential of the measurement subject who has the charging potential measuring instrument A of this embodiment is continuously measured, and an alarm or the like is issued accordingly.

More specifically, first, when the person to be measured is not charged, no current flows through the resistor Rs of the parallel circuit 3 and the voltage Vs of the resistor Rs becomes "0". Therefore, the output level of the amplifier circuit section 18 for amplifying the voltage Vs is also "0", and the integrator 3 for inputting and integrating the same
The output of 1 is basically maintained at 0 level. However, since the integrator 31 also integrates the offset voltage of the operational amplifier (not shown) constituting the integrator 31, the integrated value of the offset voltage (which increases with the passage of time) is output from the integrator 31.

On the other hand, in such an operation, the reset circuit section 20 has a predetermined period (60 seconds in this embodiment) applied to the one-shot pulse generator 38 from the oscillator 37 with a frequency divider. By the pulse, the one-shot pulse generator 38 outputs a reset command signal to the analog switch switching circuit 41 every predetermined period. At this time, the analog switch switching circuit 41 temporarily (every several ms) each time the reset command signal is received (every predetermined period).
(Around) The analog switch 30 is turned off and the analog switch 32 is turned on, thereby resetting the output of the integrator 31.

Therefore, when the person to be measured is not charged, the output of the integrator 31 becomes as shown by the solid line a in FIG. In FIG. 5, Vw1 and Vw2 are a reference low level (0.08V in this embodiment) and a reference high level (0.5V in this embodiment), respectively, which are compared with the output of the integrator 31 in the comparison circuit section 21. Yes, T is the cycle of the reset command signal of the one-shot pulse generator 38 (60 seconds in this embodiment, hereinafter,
Reset period). In the present embodiment, the integrated value of the offset voltage within the reset period T in which the integrator 31 is reset is at most about 4.2 mV, which is sufficiently higher than the reference low level VW1 and the reference high level VW2. small.

The integrated value of the offset voltage output from the integrator 31 within the reset period T when the person to be measured is not charged as described above is the reference low level VW1.
Is smaller than the reference high level VW2, the comparison circuit unit 21
The above warning signals are not output from
The warning LED lamps 14 to 17 are not lit and the piezoelectric buzzer 9 is not sounded.

Next, while the charging potential measuring instrument A is operating as described above, the person to be measured has, for example, a charging potential (8) of a magnitude corresponding to the reference low level VW1 (0.08V).
If the charging is performed with a charging potential larger than 0 V) and with a charging potential smaller than the charging potential (500 V) corresponding to the reference high level VW2 (0.5 V), the output of the integrator 31 becomes For example, as shown by the solid line b in FIG. 5, the reference low level VW1 is exceeded at some midpoint in the reset period T, and finally reaches a level substantially corresponding to the charging potential of the measurement subject.

In this case, when the output of the integrator 31 exceeds the reference low level VW1, the comparator 34 or 3 of the comparison circuit section 21 is used.
6 outputs a + side preliminary warning signal (when the charging potential is + side) or a − side preliminary warning signal (when the charging potential is − side). At this time, since the preliminary warning signal is given to the LED drive circuit 43 or 44 of the display circuit section 22 through the inverter circuit 48 or 49, the LED drive circuit 43 or 44 causes the warning LED 15 or 16 to operate as described above. Turn on the light.

At this time, the inverter circuits 48, 49
The output level of the OR circuit 51 to which the output of
The level becomes a level and is applied to the piezoelectric buzzer drive circuit 53 as a drive command signal for the piezoelectric buzzer 9. Therefore, the piezoelectric buzzer drive circuit 53 causes the piezoelectric buzzer 9 to ring. In this case, the ringing of the piezoelectric buzzer 9 is performed intermittently.

Further, the H-level signal output from the OR circuit 51 is given to the analog switch changeover circuit 41 as a reset prohibition signal. In this case, the analog changeover switch circuit 41 is a one-shot pulse generator. The output of the integrator 31 as described above is not reset regardless of the reset command signal given from the controller 38 every reset cycle T. Therefore, the output of the integrator 31 is
After exceeding the reference low level Vw1 due to the charge of the measurement target person, as long as the charge state of the measurement target person continues as it is, it continues almost constantly at a level corresponding to the charge potential of the measurement target person. LED 15 or 16 for alarms such as
Lights up and the piezoelectric buzzer 9 continues to ring. This allows
An alarm is given to the person to be measured (hereinafter, an alarm in this case is referred to as a preliminary alarm), and the person to be measured recognizes that the person himself / herself is charged to an unfavorable charging potential. Further, the output of the integrator 31 is periodically reset by the reset cycle T before the measurement target person is charged, so that the output of the integrator 31 is included in the output of the integrator 31 immediately after the measurement target person is charged. The integrated value of the offset voltage has a sufficiently small level. Therefore, the output of the integrator 31 when the warning LED 15 or 16 is turned on and the piezoelectric buzzer 9 is rung accurately indicates the charging potential of the measurement target person, and the measurement target person measures the reference low voltage. When charged with the charging potential corresponding to the level Vw1, it is possible to properly perform the preliminary alarm by lighting the alarm LEDs 15 or 16 and intermittently ringing the piezoelectric buzzer 9. When the charging time of the measurement target person as described above occurs, for example, near the end of the reset cycle T, the integrator 31 outputs a voltage before the output of the integrator 31 reaches the reference low level Vw1. It may be reset, but such a case will be described later.

When the output of the integrator 31 exceeds the reference low level Vw1, the integrator 31 is not reset. Therefore, if the charged state of the person to be measured continues at a constant charged potential, Since the offset voltage is continuously integrated, the output of the integrator 31 continuously and gradually increases. However, in general, when the person to be measured stops motions such as walking or working, the electric charge charged to the person to be measured spontaneously discharges through his / her own footwear, floor, etc., and his / her charged potential decreases. , Eventually the charge is eliminated. Therefore, as described above, when a preliminary alarm is issued by lighting the alarm LEDs 15 or 16 and ringing the piezoelectric buzzer 9, if the measurement target person stops the operation, or if the measurement target person is forcibly grounded, the measurement target The charge potential of the operator decreases, and the integrator 3
The output of 1 also decreases. Therefore, the output of the integrator 31 becomes lower than the reference low level Vw1 and is reset again, and the subsequent measurement of the charged potential of the measurement subject can be continued.

Next, the person to be measured has, for example, a charging potential (50 V) of a magnitude corresponding to the reference high level VW2 (0.5 V).
When charged with a charging potential larger than 0 V), the output of the integrator 31 becomes, for example, as shown by the solid line c in FIG.
W1 and the reference high level Vw2 are sequentially exceeded, and finally reach a level substantially equivalent to the charging potential of the measurement subject.

In this case, first, when the output of the integrator 31 exceeds the reference low level VW1, as described above, the alarm L
An alarm is issued by turning on the ED 15 or 16 and ringing the piezoelectric buzzer 9. Further, the H-level reset prohibition command signal is given from the OR circuit 51 to the analog switch switching circuit 41, so that the periodic reset of the integrator 31 is stopped.

Next, when the output of the integrator 31 exceeds the reference high level Vw2, the + side main alarm signal (when the charging potential is + side) or the-side main line is output from the comparator 33 or 35 of the comparison circuit section 21. An alarm signal (when the charging potential is on the negative side) is output. At this time, since this warning signal is given to the LED drive circuit 42 or 45 of the display circuit section 22 via the inverter circuit 47 or 50, the LED drive circuit 42 or 45 causes the warning LED 14 or 17 to be output as described above. Turn on the light.

At this time, the inverter circuits 47, 50
The output level of the OR circuit 52 to which the output of
The level becomes a level and is applied to the piezoelectric buzzer drive circuit 53 as a drive command signal for the piezoelectric buzzer 9. Therefore, the piezoelectric buzzer drive circuit 53 causes the piezoelectric buzzer 9 to continuously ring.

Since the output of the OR circuit 51 is maintained at H level, the periodic reset of the integrator 31 is stopped.

Therefore, after the output of the integrator 31 exceeds the reference high level Vw2 due to the charging of the measurement subject, as long as the charge state of the measurement subject continues as it is, the measurement subject is almost constantly. Then, the warning LED 14 or 17 and the piezoelectric buzzer 9 continue to be lit as described above. As a result, an alarm is given to the measurement target person (hereinafter, an alarm in this case is referred to as a main alarm), and the measurement target person recognizes that the measurement target person is charged to the charging potential at which the charge should be removed. Also in this case,
Similar to the case of the preliminary alarm, the output of the integrator 31 is periodically reset by the reset cycle T before the person to be measured is charged, so that the integration when the main alarm is issued is performed. The output of the container 31 accurately indicates the charging potential of the measurement subject, and the alarm can be properly performed when the measurement subject is charged with the charging potential corresponding to the reference high level Vw2. it can.

When the output of the integrator 31 exceeds the reference low level Vw1 and the reference high level Vw2, the integrator 31 is not reset. Therefore, as in the case of the above-mentioned preliminary alarm, the integrator 31 is not reset. Although the output continuously increases gradually due to the integration of the offset voltage, when the alarm is issued as described above, it is in a state where the charge of the measurement target person should be removed. Is forcibly grounded to eliminate static electricity. And if the static elimination is done like this,
Similar to the case of the above-mentioned preliminary alarm, the output of the integrator 31 becomes lower than the reference low level Vw1 and is reset again, and the subsequent measurement of the charged potential of the measurement subject can be continued. In this case, the reset switch 13 may be operated, and when the reset switch 13 is operated, a reset command signal given from the reset signal generation circuit 40 to the analog switch switching circuit 41 causes
The analog switch switching circuit 41 resets the integrator 31.

By the way, in the charging potential measuring instrument A of the present embodiment, the charging potential of the person to be measured is temporarily and gradually increased, and the output of the integrator 31 according to the charging potential (here Then, the integrated value of the offset voltage is excluded), but as shown by a virtual line d in FIG. 5, for example, as shown by a phantom line d, the slope gradually increases so as not to reach the reference low level Vw1 within the reset period T. If it goes up, the output of the integrator 31 is reset before the output of the integrator 31 reaches the reference low level Vw1. Therefore, the preliminary alarm and the main alarm according to the charged potential of the measurement subject should be issued. There is a risk that you will not be able to. It should be noted that if the charge potential of the measurement subject greatly rises within the next reset period T after the reset of the integrator 31, a preliminary alarm or a main alarm can be issued.

Further, even in the case of charging the measurement subject as shown by the solid lines b and c in FIG. 5, the time when the measurement subject is charged is near the end of the reset cycle T. In such a case, the integrator 31 may be reset before the output of the integrator 31 reaches the reference low level Vw1. In such a case, when the measurement subject is charged as shown by the solid line c, that is, when the charge is larger than the charging potential corresponding to the reference high level Vw2, the output of the integrator 31 is in the middle of rising. Therefore, even if the integrator 31 is reset, the output of the integrator 31 rises to at least the reference low level Vw1 or more within the next reset period T, and a preliminary alarm can be given. If the charging potential of 1 is sufficiently large, the output of the integrator 31 will exceed the reference high level Vw2 and the alarm can be issued. Therefore, there is no problem in practical use. On the other hand, when charged with a charging potential slightly larger than the charging potential corresponding to the reference low level Vw1 (as indicated by the solid line b in FIG. 5), the output of the integrator 31 increases while the output of the integrator 31 increases. When 31 is reset, the output of the integrator 31 cannot reach the reference low level Vw1 within the next reset cycle T, and the preliminary alarm is not issued as in the case of the virtual line d in FIG. May occur.

However, in general, the charge potential of the measurement subject hardly rises continuously over a long period of time. That is, in general, the charge of the measurement target person is caused by a friction phenomenon or the like during movement such as walking or work, and if the measurement target person stops the operation and stops, the charge charged on the measurement target person is in the footwear. Or through the floor. The discharge time is generally about several tens of seconds.

If the footwear, the floor, etc. of the person to be measured are highly insulating, the electrification of the person to be measured progresses rapidly, so that the integrator 3 is relatively short in time.
The output of 1 rises to a level exceeding the reference low level Vw1 and the reference high level Vw2.

Therefore, if the reset cycle T is set to a relatively long time in consideration of the integration of the offset voltage, the charge potential of the measurement subject becomes a level corresponding to the reference low level Vw1 or the reference high level Vw2. When charged to a potential exceeding the level, the output of the integrator 31 is almost certainly reset period T
The preliminary alarm and the main alarm are issued when the reference low level Vw1 and the reference high level Vw2 are exceeded.

Further, even if the output of the integrator 31 corresponding to the charging potential of the measurement subject may increase with the increase degree shown by the phantom line d in FIG. Before the charged potential reaches at least the potential corresponding to the reference high level Vw2, the measurement subject stops the operation,
Alternatively, if you ground yourself, there is no practical problem. This means that in the case of charging the measurement subject as shown by the solid lines b and c in FIG. 5, the integrator 31 is activated before the preliminary alarm is issued while the output of the integrator 31 is increasing as described above.
The same is true when is reset.

In this case, the time until the charging potential of the person to be measured reaches the potential corresponding to the reference high level Vw2 without the preliminary alarm being issued is the integrator 3 according to the charging potential.
The output of 1 is the reference low level V within the reset cycle T.
It becomes shortest when rising to a level slightly smaller than w1, and when the time is Tx as shown in FIG. 5, Tx≈ (Vw2 / Vw1) · T, and in this embodiment,
The time Tx is about 6 minutes. Therefore, if the measurement target person stops the operation or grounds himself / herself about every 6 minutes, the charged potential of the measurement target person is surely the potential corresponding to the reference high level Vw2 at which the main alarm should be issued. The charging potential of the person to be measured decreases before the temperature reaches. This allows
It is possible to reliably avoid a situation in which the main alarm is not issued in the state where the charged potential of the measurement subject reaches the potential corresponding to the reference high level Vw2 at which the main alarm should be issued. Further, if the charge potential of the measurement subject decreases, subsequent measurement of the charge potential of the measurement subject can be continuously performed while periodically resetting the integrator 31 as described above.

As described above, according to the charging potential measuring instrument A of the present embodiment, while the charging potential of the person to be measured is continuously grasped by the output of the integrator 31, a preliminary alarm and a main alarm corresponding to the charging potential are issued. It can be done properly.

In the charging potential measuring instrument A of this embodiment, the voltage VD of the battery 10 is compared with a predetermined lower limit level by the comparator 55 of the power source voltage monitoring circuit section 24 during its operation. When the voltage VD falls below the lower limit level, the LED drive circuit 56 causes the power supply monitoring LED lamp 12 to blink from the lit state in accordance with the output signal of the comparator 55. Further, at this time, the piezoelectric buzzer driving circuit 53 causes the piezoelectric buzzer 9 to ring in response to the command signal given from the LED driving circuit 56. As a result, the person to be measured is informed of the necessity of replacing the battery 10.

In the embodiment described above, it is needless to say that the value itself of the charged potential of the measurement subject can be displayed on an appropriate display device based on the output of the integrator 31.

Further, in this embodiment, the resistance R of the parallel circuit 3 is
Although the voltage Vs of s is integrated, the current flowing through the resistor Rs may be detected by using an appropriate current sensor and the charge potential of the measurement object may be grasped by integrating the current.

In the present embodiment, the object to be measured is the human body and the charging potential is measured, but the present invention is not limited to this, and the charging potential of various charged objects may be measured. It is possible. In this case, the electrostatic capacitance between the second conductor connected to the first conductor facing the object to be measured through a parallel circuit composed of a resistor and a capacitor and a reference potential portion such as the ground becomes a constant value. By configuring the measuring device as described above and integrating the voltage of the resistance of the parallel circuit by using the integrator as in the above-described embodiment, the charging potential of the measuring object can be grasped from the integrated value.

[0097]

As is apparent from the above description, according to the present invention, the first conductor which is arranged to face the object to be measured and the second conductor which is arranged so as to form a substantially constant capacitance in the external environment are provided. Connected via a parallel circuit consisting of a resistor and a capacitor in a state of being substantially insulated from each other, the current flowing through the resistance of the parallel circuit or the voltage of the resistor is integrated by integrating means when charging the measurement object, and the integrated value of the measurement object Since the charging potential is grasped, it is possible to measure the charging potential of a measurement target such as a human body without the need for grounding the measuring device. Moreover, even when the measurer detects and grasps the self-charged potential while carrying the measuring instrument, the measurer can continuously measure the self-charged potential while continuously possessing the measuring device. Therefore, it is possible to provide a simple and convenient charging potential measuring device.

When the charging potential measuring instrument of the present invention is used in, for example, a semiconductor production line, the alarm means gives an alarm when the integrated value obtained by the integrating means exceeds a predetermined value. In addition, the excessive charging of the measurement target can be easily grasped by the alarm, and appropriate measures such as grounding of the measurement target according to the alarm can be appropriately applied.

Further, when the integrated value obtained by the integrating means is equal to or less than a predetermined value and the integrated value is periodically reset by the resetting means, the integrating means is constructed by using an operational amplifier. In addition, the integrated value obtained by integrating the offset voltage of the operational amplifier by the integrating means can always be suppressed to a sufficiently small level,
Accordingly, when the measurement target is charged, the charging potential of the measurement target can be accurately grasped from the integrated value of the integrating means.

Further, the case of the charged potential measuring instrument of the present invention is constituted by including the first conductor and the second conductor fixed to each other by an insulator, and the case is a pocket of a clothing of a human body to be measured. Since it is formed so that it can be stored in the storage part, the person to be measured can carry the charge potential measuring device while carrying it while carrying the charging potential measuring device by simply storing the charging potential measuring device in the storage part such as a pocket of clothing. At the same time, the self charging potential can be continuously grasped without any trouble.

Therefore, according to the present invention, it is possible to provide a simple and convenient charging potential measuring device. In particular, in a semiconductor manufacturing line or the like, a person who is moving or working can measure the self-charging potential. It is possible to provide an optimum charging potential measuring device for measurement.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an electrical configuration for explaining an operating principle of a charging potential measuring device of the present invention.

FIG. 2 is a circuit diagram showing an electrical equivalent circuit of the schematic diagram of FIG.

FIG. 3 is an external perspective view of an embodiment of the charging potential measuring device of the present invention.

FIG. 4 is a block diagram showing a circuit configuration of a main part of the charging potential measuring device of FIG.

FIG. 5 is a diagram for explaining the operation of the charging potential measuring device of FIG.

[Explanation of symbols]

1 ... 1st conductor, 2 ... 2nd conductor, 3 ... Parallel circuit, 4 ... Housing, 7 ... Insulator, Cs ... Capacitor, Rs ... Resistor, 19
... integrating means, 26 ... charge potential grasping means, 27 ... warning means, 20 ... resetting means.

Claims (4)

[Claims] 1. A first device, which is arranged so as to face a target for measuring a charging potential.
A parallel circuit including a conductor and a resistor and a capacitor connected to the first conductor; and a parallel circuit that is provided so as to be substantially insulated from the measurement target and the first conductor and through the parallel circuit.
The resistance of the parallel circuit when the second conductor, which is connected to the conductor and is arranged at a position where a substantially constant electrostatic capacitance is formed between the conductor and the outside during measurement, and the first conductor are arranged so as to face the measurement target. Integrating means for integrating the current flowing through or the voltage of the resistance, and charging for grasping the charging potential of the measuring object by the integral value as an amount proportional to the charging potential of the measuring object obtained by the integrating means. A charging potential measuring instrument comprising: a potential grasping means. 2. The charging potential grasping means comprises alarm means for issuing an alarm when the integrated value of the integrating means indicating the charging potential of the measuring object exceeds a predetermined value. Charge potential measuring instrument. 3. A charging potential measuring instrument according to claim 1, further comprising reset means for periodically resetting the integrated value obtained by said integrating means when the integrated value is below a predetermined value. . 4. The body to be measured is a human body, the first conductor and the second conductor are fixed to each other through an insulator, and a housing for accommodating the parallel circuit, the integrating means, and the charging potential grasping means therein. A body is formed by including the first conductor and the second conductor in a part of the body, and the case is provided in the storage portion of the clothing with the first conductor.
The charging potential measuring device according to claim 1, wherein the conductor is formed so as to face toward the human body and the second conductor can face toward the side away from the human body.