JPH04102001A - Electrostatic detector - Google Patents

Abstract

PURPOSE:To enable non-contact detection of a sheet-shaped article by traversing the article across an electric field produced by a detecting electrode when the article passes through a section of the detecting electrode. CONSTITUTION:Formed between a sensor body 8 and a stage 2 is a gap 9 which passes a sheet-shaped article 1 with no contact. A circuit board 12 is covered by a shield case 13 made of conductor, and enclosed in housing 10. A stage 2 constitutes a ground potential plane 23. The presence of the ground potential plane 23 acting as an imaginary short-circuit to the shield case 13, creates an electric field from a detecting electrode 20 to the ground potential plane 23. The sheet-shaped article traversing the electric field produces a state equivalent to the state in which the sheet-shaped article 1 traverses the electric field directing from the detecting electrode 20 to the shield case 13, where a change in dielectric constant of the detecting electrode 20 and the ground potential plane 23 is directly detected by the detecting electrode 20 as a change in electrostatic capacity. In this way, the electrostatic sensor circuit produces a thickness detection signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrostatic detection device for detecting the thickness of paper sheets such as banknotes and copy paper.

[Conventional technology]

2. Description of the Related Art Devices using potentiometers are widely used as devices for detecting the thickness of sheets of paper such as cloth and paper. As shown in FIG. 14, this type of device is constructed by disposing a potentiometer 3 on a stage 2 on a path through which a paper sheet 1 passes. This potentiometer 3 is connected to the rotating shaft 4
Attach arm 5 to the arm, and attach roller 6 to the tip of the arm.
is rotatably attached, and a spring 7 is used to constantly urge the roller 6 toward the stage 2 side. In the state shown in FIG. 14, when the paper sheet 1 moves in the direction of the arrow, the roller 6 rides on the paper sheet 1 and rotates the arm 5 clockwise. The rotation of this arm 5 is the rotation axis 4.
As a result, an output voltage proportional to the amount of rotation of the arm 5, that is, the thickness of the paper sheet weight, is output as a thickness detection signal of the paper sheet 1, as shown in FIG.

[Problem to be solved by the invention]

However, in the method of detecting the thickness of the paper sheet 1 with the potentiometer 3, the amount of rotation of the arm 5 corresponding to the thickness of the paper sheet 1 is very small, and therefore the output voltage level from the potentiometer 3 is also very small. However, there is an inconvenience in that the thickness of the paper sheet 1 such as thin paper cannot be detected with high accuracy.

In addition, when the paper sheet l is conveyed at high speed, when the roller 6 rides on the paper sheet 1, an extra movement occurs due to the reaction, and as shown in FIG. 15, the output voltage waveform changes. There is an inconvenience that overshoe P appears.

In order to prevent such an overshoe P from occurring, it is necessary to make the biasing force of the spring 7 very strong, and in this case, the roller 6 will come into strong contact with the stage 2, which will cause the paper sheet 1 to be transported in the conveyance system. This causes a problem in that it becomes a load and the power consumption of the transport system increases.

Furthermore, in order to accurately detect the thickness using this type of potentiometer 3, it is necessary to attach the roller 6 to the stage 2 in the X direction, which is the running direction of the paper sheet 1, and in the Y direction, which is perpendicular to the traveling direction on the plane. The assembly was extremely difficult, as it had to be assembled with high precision to avoid even the slightest inclination in the vertical Z direction.

Furthermore, for example, when transporting banknotes one by one, 2
When detecting the overlapping state based on paper thickness, it is necessary to arrange a plurality of rollers 6 closely in the width direction of the paper sheet 1 to detect the thickness of the paper sheet 1 over the entire width. However, as is well known, since the potentiometer 3 has a large dimension in the width direction, it is inconvenient that the rollers 6 cannot be arranged in the width direction of the paper sheet 1 with high density.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to be able to detect the thickness of a paper sheet in a non-contact manner, and to solve various problems caused by the conventional potentiometers. An object of the present invention is to provide an electrostatic detection device that can effectively eliminate the problem.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention includes an oscillation circuit and a resonator separate and independent from the oscillation circuit, changes a tuning point in response to a change in external capacitance, and outputs a detection signal corresponding to the change in the tuning point. An electrostatic sensor circuit having a tuned circuit is covered by a shield case connected to the ground potential of the electrostatic sensor circuit, and a detection electrode is connected to the resonator of the tuned circuit, and the detection electrode The detection tip of the electrostatic sensor is characterized in that the detection tip protrudes toward the outside of the shield case, and is configured such that the object to be detected passes through an electric field formed by the detection electrode. The shield case that covers the circuit is housed inside the case, and the detection electrodes are connected to the first electrode and the second electrode.
The first electrode is fixed to the circuit board of the electrostatic sensor circuit, the second electrode is fixed to the casing side, and one of the first electrode and the second electrode is fixed to the spring body. It is also a characteristic structure of the present invention that the first electrode and the second electrode are pressure-connected by the elastic restoring force of the spring body. Another characteristic feature of the present invention is that the second electrodes are electrostatically connected to face each other through a minute gap.Furthermore, a stage is provided opposite the tip of the detection electrode, and the stage is connected to the ground. The characteristic configuration of the present invention is that it is formed on a potential surface.

[Effect]

In the above configuration, when the paper sheet is conveyed along the passage path and attempts to pass the detection electrode portion, the object to be detected crosses the electric field formed by the detection electrode. In this way, when the object to be detected enters the electric field region, the dielectric constant of the electric field region changes. In other words, the dielectric constant of the object to be detected is added to the spatial dielectric constant. When a plurality of objects to be detected overlap, the change in dielectric constant increases depending on the number of objects to be detected. In this way, the dielectric constant of the electric field forming space changes depending on the thickness of the object to be detected across the electric field, and the capacitance changes in accordance with the change in the dielectric constant. This change in capacitance causes the tuning point of the tuning circuit to change, and a voltage signal corresponding to this change in tuning point is output from the electrostatic sensor circuit as a sheet thickness detection signal.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
A first embodiment of the electrostatic detection device according to the present invention is shown in FIGS. In these figures, a sensor body 8 is disposed on a stage 2 of a passage path of a conveyance system through which a paper sheet 1 such as a banknote, copy paper, plastic film, or cloth passes. Then, the sensor main body 8 and the stage 2
A gap 9 is formed between them, through which the paper sheet 1 passes without contact. The sensor main body 8 accommodates a circuit board 12 on which an electrostatic sensor circuit is formed in an accommodation recess 11 of the national body IO. The national body 10 is formed of an insulating member such as a metal plate covered with synthetic resin or an insulating material. The circuit board 12 is a conductor shield case 1.
3, and the circuit board 12 is housed in the national body 10 in a state covered with a shield case 13.

FIG. 3 shows an example of an electrostatic sensor circuit formed on the circuit board 12. This electrostatic sensor circuit includes an oscillation circuit 14 and a ceramic resonator 15 functioning as a tuning circuit.
, the detection circuit 16, the amplifier circuit 17, and the AFC(A
Automatic Frequency Control
l) circuit 18, and the ground plane of this circuit is connected to the shield case 13. Here, the ground potential refers to a potential that is in an imaginary short-circuit state with the earth at high frequency. The oscillation circuit 14 has a built-in ceramic resonator 19, and has a frequency of 0.5GHz to 10G.
Although it was decided to output an ultra-high oscillation frequency signal of IGHz in this embodiment, a frequency between 0.5 and 10 GHz is selected depending on the applied device.

A detection electrode 20 is connected to the output terminal side of the ceramic resonator 15 that functions as a tuning circuit. This detection electrode 20 is fixed to the circuit board vi12 by soldering or the like,
Its detection tip surface is projected outward from the national polity. The ceramic resonator 15 changes the tuning point with the oscillation circuit 14 in response to the change in capacitance detected by the detection electrode 20, and generates a voltage signal corresponding to the change in the tuning point using the oscillation frequency of the oscillation circuit as a carrier wave. output as an amplitude modulated signal. The detection circuit 16 detects the amplitude modulation signal output from the ceramic resonator 15, converts it into a signal in the thickness detection signal band of the paper sheet 1, and applies this to the amplifier circuit 17. The amplifier circuit 17 amplifies the detected output and supplies it to a desired signal processing circuit. The AFC circuit 18 corrects changes in the tuning point of the ceramic resonator 15 due to environmental changes, etc., and stabilizes the tuning point of the ceramic resonator 15.

In this embodiment, the bottom surface of the national polity 10 is the reference surface 10a, and the tip end surface of the detection electrode 20 is placed on this reference surface 10a, so that the tip side of the detection electrode 20 is placed in the electrode insertion hole 2 of the national polity 10.
A mounting hole 22 is provided at an appropriate position of the zero body 10 accommodated in the sensor body 8, and the sensor body 8 is mounted using one of the holes 22 as shown in FIG. It is fixed to the upper side of the stage 2 so that its rotational position can be adjusted. The stage 2 is made of a suitable material such as a metal plate or a plastic plate, and in this embodiment, the stage 2 constitutes the ground potential plane 23. Generally, when a circuit is driven by an ultra-high frequency signal on the order of IGHz, a type of capacitor functions strongly between the shield case 13 and the ground potential surface 23, and this capacitor acts as a capacitor when driving the ultra-high frequency signal. is in an imaginary short state with respect to the shield case 13, and the shield case 13 and the ground potential plane 23 become the same potential plane.

Generally, an electric field is generated between the detection electrode 20 and a ground potential part close to it, and when the paper sheet 1 crosses this electric field, the dielectric constant between the detection electrode 20 and the ground potential part changes, and this causes electrostatic This is detected by the detection electrode 20 as a change in capacitance. By further developing this principle and providing a ground potential plane 23 that is imaginary short to the shield case 13, it is possible to connect the detection electrode 20 to the ground potential plane 23.
3, and when the paper sheet 1 crosses this electric field, the electric field from the detection electrode 20 toward the shield case 13 becomes in a state equivalent to the state where it is crossed by the paper sheet 1, and the detection electrode 20 and ground A change in dielectric constant with respect to the potential surface 23 is directly detected from the detection electrode 20 as a change in capacitance. By providing the ground potential surface 23 in this way, it is extremely easy to set the path between the ground potential surface 23 and the detection electrode 20 as a passage for the paper sheet 1.
It becomes possible to easily create a device for detecting the thickness of the paper sheet 1. FIG. 4 shows various shapes of the detection electrode 20, and a shape suitable for the purpose of use is used6.For example, when detecting the thickness over the entire width of the paper sheet 1, When using wide detection electrodes as shown in FIGS. 4(d) to (6) to detect the local minute thickness of the paper sheet 1, the electrodes with a small width as shown in FIG. 4(i) are used. electrodes will be used.

FIG. 5 shows an example of paper thickness detection by the apparatus of this embodiment, and FIG. 6 shows the paper thickness detection results. First, when the paper sheet 1 made of a sheet of paper passes between the stage 2 functioning as the ground potential plane 23 and the detection electrode 20, a voltage level change corresponding to the thickness of the sheet of paper appears. Next, the two overlapping paper sheets 1 are placed on the detection electrode 2.
0 and stage 2, the permittivity of the space where the electric field is formed increases by the thickness of each sheet of paper, and as a result, the output signal corresponding to the thickness of the two sheets becomes static. Output from the electric sensor circuit. Therefore, by analyzing the output change of this electrostatic sensor circuit, it becomes possible to accurately determine the thickness of the paper sheet 1 as the object to be detected in a non-contact state.

A second embodiment of the sensor main body portion 8 is shown in FIGS. 7 to 1O. In this second embodiment, the national body 10 is formed in half into a main body side and a lid side, a locking step 24 is formed in the accommodation recess 11, and a presser claw 2 is provided on the upper end side of the accommodation recess 11.
5 protrudes inward, and the detection electrode 20 is divided into a first electrode 20a and a second electrode 20b, and as shown in FIG. 9, the first electrode 20a has a spring shape. The second electrode 20b is formed into a columnar shape, and the tip end surface of the second electrode 20b is aligned with the reference surface 10a of the national body 10, and the base end side thereof is fixed to the circuit board 12 side. 21
It is fixed at .

In this second embodiment, when the shield case 13 is accommodated in the accommodation recess 11 by pushing the presser claws 25 upwardly,
The shield case 13 is pushed downward by the elastic restoring force of the presser claw 25, and its lower end surface is locked by the locking step 24 and positioned. At this time, the first electrode 20a is brought into pressure contact with the second electrode 20b by the elastic restoring force of the spring, and a conductive connection between the first electrode 20a and the second electrode 20b is achieved.

When the detection electrode 20 is integrally constructed as in the first embodiment, it is very difficult to align the detection electrode 20 when fixing it to the circuit board 12, and the detection electrode 20 may be shifted in the vertical direction, for example, and the detection electrode There is a vibration that causes a problem in that the length of the conductor portion from the tip end surface of the ceramic resonator 20 to the ceramic resonator 15 deviates from the set value. The length of this conductor portion is preferably smaller than nλ/4 (n is an integer of 1 or more), where λ is the wavelength of the resonant frequency of the ceramic resonator 15. This is because when nλ/4 is reached, the stability of the resonance frequency of the ceramic resonator 15 deteriorates. When the driving frequency of the circuit becomes extremely high, if the position of the vertical mounting of the detection electrode 20 is slightly shifted, the length of the conductor part will tremble and fall into the length region of nλ/4. In this case, a problem arises in that reliability in detecting the thickness of the paper sheet 1 is lost. In this respect, as in this second embodiment, the detection electrode is divided into the first electrode 20a and the second electrode 20b, and the picture electrode 20a, 20b
By making use of the restoring force of the spring to conductively connect the detection electrodes 200 to the circuit board 12, it is possible to solve the problem of misalignment when mounting the detection electrodes 200 to the circuit board 12, and it is also possible to solve the problem of mounting the detection electrodes 200 to the circuit board 12. can be facilitated. In this second embodiment, the accommodation recess 11 on the main body side
After the shield case 13 is housed in the container, the lid side of the national polity is put on, and the main body side and the lid side are joined together by screws or the like.

The national polity 10 can be constructed in various shapes other than being divided into halves. For example, as shown in FIG. The shield case 13 is inserted into the housing recess 11 from above in the direction of the arrow, and when the upper end surface of the shield case 13 is inserted over the locking protrusion 26, the lower end surface of the shield case 13 is engaged. It is locked to the stop part 24, and the national polity 1
The second electrode 20b on the 0 side and the first electrode 20a on the circuit board 12 side may be electrically connected by the restoring force of the spring. Also, at this time, the locking protrusion 26 is omitted, and for example, a screw is brought into contact with the upper end side of the shield case 13 from the upper end side of the national body 10, and the screw is screwed and advanced to attach the shield case 13 to the locking stepped portion 24. Alternatively, the shield case 13 may be placed in a mold with the first electrode 20a and the second electrode 20b connected by pressure contact, and the shield case 13 may be positioned on the national body 10. In this state, the shield case 13 can be formed integrally with the national polity 10 by injecting synthetic resin into the mold.

In addition, in FIG. 9, the first electrode 20a side is formed of a spring body, but for example, as shown in FIG.
The electrode 20b is formed into a spring body (a plate spring shape in the figure), and the elastic restoring force of the second electrode 20b causes the first electrode 20
a and the second electrode 20b may be electrically connected in a press-contact state, and in some cases, the spring portion acts as a coil to remove stray capacitance.

FIG. 11 shows a case in which the detection electrode 20 is not divided as in the first embodiment, and a case in which it is divided into a first electrode 20a and a second electrode 20b as in the second embodiment. The equivalent circuit of each is shown.

When the detection electrode 20 is configured without being divided, the 11th
As shown in Figure (a), the equivalent circuit is the detection electrode 20
, a capacitance c6 that depends on the thickness of the object to be detected, that is, the paper sheet 1 in this embodiment, and a capacitance CL that depends on the accuracy of the vertical mounting of the detection electrode 20 to the circuit board 12. becomes a series circuit.

On the other hand, when the detection electrode 20 is divided, the 11th
As shown in Figure (b), the resistance R□ of the first electrode 20a, the contact resistance Re at the contact portion between the first electrode 20a and the second electrode 20b, and the capacitance C at the contact portion
3, the resistor R1 of the second electrode 20b, and the capacitor C4 of the object to be detected form a series circuit.

At this time, Rc << Rt + + Rt t ,
Since Ca>>Ce, the equivalent circuits in FIGS. 11(a) and 11(Cb) are approximately the same, and the detection electrode 2
Even when 0 is divided, the same signal level as when not divided can be obtained. Therefore, by forming the detection electrode 20 in parts, it is possible to avoid the difficulty of attaching the detection electrode to the circuit board, and it is also easier to incorporate the shield case I3 into the national body 10. The efficiency of assembly work can be improved.

FIG. 12 shows a third embodiment of the sensor body of the electrostatic detection device according to the present invention. In this third embodiment, similarly to the second embodiment, the detection electrode 20 is divided into a first electrode 20a and a second electrode 20b, and the first
The base end side of the electrode 20a is connected and fixed to the circuit board 12 side,
The second electrode 20b is fixed in the electrode insertion hole 21 of the national polity 10, and the abutting end surfaces of the first electrode 20a and the second electrode 20b are protruded like a brim to increase the planar area.
The large-diameter planes of the electrode 20a and the second electrode 20b are opposed to each other with a certain gap 27 interposed therebetween, and the first electrode 20a and the second electrode 20b are electrostatically connected.

In general, when the detection electrode 20 is configured without being divided, even if the detection electrode 20 is connected and fixed to the circuit board 12 using a jig or the like, the axial direction (vertical direction in the figure) The accuracy can only be expected to be about 5/1100 = 115, and as mentioned above, due to errors in this assembly, the length of the conductor from the sensing tip of the electrode to the ceramic resonator 15 changes (nλ/4 ), there is a risk that reliability of the resonant frequency may no longer be obtained. On the other hand, in this third embodiment, the space width L1 of the gap 27 is made large such that Lh≧eA+e, +e, +e. Here, eA is the axial assembly error of the first electrode 20a, e is the axial assembly error of the second electrode 20b, e is the dimensional tolerance during manufacturing of the first electrode 20a, and C2 is the axial assembly error of the first electrode 20a. This is the dimensional tolerance during manufacturing of the second electrode.

In this way, by forming the gap 27 to a size greater than the sum of various assembly errors, the electrode 20a.

20b becomes very easy to install. Moreover, the equivalent circuit of the electrode portion at this time is expressed as shown in FIG.

In this equivalent circuit, RtI, Rt□, and c are the same as in the equivalent circuit shown in FIG. 11, and cL□ is the capacitance of the gap 27 portion. Comparing this equivalent circuit with the equivalent circuit of FIG. 11(a) (equivalent circuit when the detection electrode is not divided), C4≧CLI, but C4≧CLI,
CL! ! = iCLl, so the equivalent circuit of this third embodiment is almost the same as the equivalent circuit of FIG. 11(a) in which the electrodes are not divided, and the detection electrode is divided into the first electrode 20a and the second electrode 20b. Even if the detection electrode 20 is divided, it is possible to obtain the same detection ability as in the case where the detection electrode 20 is not divided, and it is possible to achieve the effect that the task of assembling the detection electrode can be made easier by the amount that the detection electrode is divided.

Note that the present invention is not limited to the above embodiments,
For example, in each of the above embodiments, the stage 2 is configured as a ground potential surface 23, and this ground potential surface 23 is such that the lines of electric force emitted from the detection electrode 20 are connected to the paper sheet 1. The stage 2 may be provided at a position that crosses the passage path of the stage 2, and the stage 2 does not necessarily have to be configured as a ground potential plane.

〔Effect of the invention〕

In the present invention, since the detection electrode is provided to protrude from the shield case covering the electrostatic sensor circuit, for example, when a paper sheet is conveyed along the passage path, the paper sheet is detected. By crossing the electric field formed by the electrodes,
The change in dielectric constant due to the thickness of the paper sheet can be detected as a change in capacitance by a detection electrode.In the present invention, this change in capacitance is detected by using a change in the tuning point of a tuning circuit. Therefore, it is possible to detect the thickness of a paper sheet with ultra-high sensitivity on the order of I Xl0-'PF.

Furthermore, as described above, the present invention is configured to detect the thickness of a paper sheet by generating an electric field between the detection electrode and the ground potential surface and by having the object to be detected cross the electric field. This method eliminates the difficulty of assembling the roller when using a potentiometer, as well as the problem of overshoe output due to reaction when the roller rides on the paper sheet, and it is also possible to detect the thickness of the paper sheet. Detection is possible without contacting the paper sheet, so there is no need to place a large load on the paper sheet conveyance system when detecting the thickness.Furthermore, the ground potential plane is connected to the electrostatic sensor circuit. Since only the detection electrode is connected to the electrostatic sensor circuit, it is not only easy to manufacture the device, but also very easy to handle.

Furthermore, since the device of the present invention can be formed thinner than conventional potentiometers, it is possible to mount the detection electrodes at high density in the width direction of the paper sheet, and the thickness of the paper sheet can vary in the width direction. can be detected in detail.

Further, the detection electrode constituting the device of the present invention is configured by dividing into two parts, one electrode is attached to the circuit board side of the electrostatic sensor circuit, and the other electrode is attached to the casing side.
In a configuration in which the first electrode and the second electrode are connected by spring pressure or electrostatically through a certain gap, it is very easy to assemble the device. , it becomes possible to improve the efficiency of device manufacturing and reduce device costs.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the electrostatic detection device according to the present invention, FIG. 2(a) is a longitudinal sectional front view of the sensor body of the device, and FIG. 2(b) is the sensor body of the same device. Longitudinal side view, 2nd
Figure (C) is a bottom view of the sensor main body, Figure 3 is a circuit diagram showing an example of the electrostatic sensor circuit in this embodiment, and Figure 4 is a diagram showing various forms of the detection electrodes constituting this embodiment. 5 is an explanatory diagram showing an example of detecting the thickness of a sheet of paper by the apparatus of the same embodiment. FIG. FIG. 7 is a front view showing the main parts of the second embodiment of the electrostatic detection device according to the present invention in a cross-sectional state of the national polity; FIG. FIG. 9 is an explanatory diagram of various examples of divided connection of the detection electrode in the second embodiment, FIG. 10 is an explanatory diagram showing other examples of divided connection of the detection electrode, and FIG. 11 is an explanatory diagram of the detection electrode of the second embodiment. Fig. 12 is a front view showing the main parts of the third embodiment of the electrostatic detection device according to the present invention in a cross-sectional state of the national polity. 13 is a circuit diagram showing an equivalent circuit of the detection electrode in the third embodiment, FIG. 14 is a perspective view showing a conventional thickness detecting device using a potentiometer, and FIG. 15 is a paper leaf-shaped object using a conventional device. FIG. 2 is an explanatory diagram of a thickness detection waveform. DESCRIPTION OF SYMBOLS 1... Paper sheet, 2... Stage, 3... Potentiometer, 4... Rotating shaft, 5... Arm, 6...
・Roller, 7... Spring, 8... Sensor body, 9.
...Gap, 10...National polity, 10a...Bottom surface (reference surface), 11...Accommodating recess, 12...Circuit board, 13.
...Shield case, 14...Oscillation circuit, 15...
Ceramic resonator, 16... Detection circuit, 17... Amplification circuit, 18... AFC circuit, 19... Ceramic resonator, 20... Detection electrode, 20a... First electrode, 20b ...Second electrode, 21...Electrode insertion hole, 2
2... Mounting hole, 23... Ground potential surface, 24
... Locking step portion, 25 ... Presser pawl, 26 ... Locking protrusion, 27 ... Gap. Applicant Uchide Seisakusho Co., Ltd. Representative Patent Attorney Kiyoshi Igarashi 1 Figure 4 (a) (C) (a) (+)) (d) (e) (ch) (h) (j) Figure of sheep with broom Fig. 1. Genealogical chart (continuation) (I)) Fig. 1 (cL) (C) Fig. 1.1111.

Claims (3)

[Claims] (1) A tuning circuit that includes an oscillation circuit and a resonator separate from the oscillation circuit, changes the tuning point in response to changes in external capacitance, and outputs a detection signal corresponding to the change in the tuning point. An electrostatic sensor circuit having an electrostatic sensor circuit is covered by a shield case connected to the ground potential of the electrostatic sensor circuit, and a detection electrode is connected to the resonator of the tuned circuit, and a detection tip of the detection electrode is connected to the resonator of the tuning circuit. The electrostatic detection device is configured such that the portion projects outward from the shield case, and the object to be detected passes through an electric field formed by the detection electrode. (2) The shield case covering the electrostatic sensor circuit is housed in the casing, and the detection electrode is divided into a first electrode and a second electrode, and the first electrode is attached to the circuit board of the electrostatic sensor circuit. The second electrode is fixed to the housing side, and one of the first electrode and the second electrode is constituted by a spring body, and the elastic restoring force of the spring body causes the first electrode and the second electrode to 2. The electrostatic detection device according to claim 1, wherein the two electrodes are pressure-contacted. (3) The shield case covering the electrostatic sensor circuit is housed in the casing, and the detection electrode is divided into a first electrode and a second electrode, and the first electrode is connected to the circuit board of the electrostatic sensor circuit. The second electrode is fixed to the casing side, and the first electrode and the second electrode are electrostatically connected to face each other through a minute gap. Electrostatic detection device. (4) The electrostatic detection device according to claim 1, wherein a stage is provided opposite the tip of the detection electrode, and the stage is formed on a ground potential plane.